CT scanners · CT HiSpeed family

GE Healthcare CT HiSpeed: troubleshooting and error codes

The ServiceForge knowledge base holds 301 documented symptoms for the GE Healthcare CT HiSpeed, with 363 ranked causes, 1051 diagnostic checks with test points and expected values, and 19 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

HV chain fault detection high voltage

Fast and slow safeties monitor inverter performance; fast safeties cut HV power on error; slow safeties measure signals every 1 ms for fault detection

Ranked causes

1. Over kV condition (common)
2. No kV condition (common)
3. kV regulation error at 7th error in exposure (occasional)
4. Anode spit exceeds max allowed count (occasional)
5. Cathode spit exceeds max allowed count (occasional)
6. Max resonant current exceeded (occasional)
7. Gate supply out of range (occasional)

First check

Monitor kV measurement

Test point: kV measure signal
Expected: Within safe operating range

3 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

TGP board does not initialize on power-on

After powering on or resetting TGP board, processor fails to complete ROM and RAM tests; ERRG, LPG, RQG, ERRT, LPT, RQT, MNT, ERRM, LPM, RQM, or MNM LEDs light and remain on

Ranked causes

1. Gantry processor RAM check failure (U87, U92, U77) (rare)
2. Gantry processor ROM check failure (U112) (rare)
3. Table processor RAM check failure (U42, U64, U48) (rare)
4. Table processor ROM check failure (U68) (rare)
5. Management processor RAM check failure (U88, U62, U48, U77) (rare)
6. Management processor ROM check failure (U111) (rare)

First check

Observe gantry processor LED status on TGP board after power-on

Test point: ERRG, LPG, RQG LEDs on TGP board
Expected: LPG LED should blink after successful RAM and ROM checks; ERRG LED indicates hang up state

2 more checks with pass and fail actions, 6 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Miscellaneous Hardware Tests patient safety

Operator Console miscellaneous tests including Hardware Inventory, SCSI Test, System Log viewing, NPR LED Test, Safety Loop test, and Shutdown test to verify system configuration and relay operation.

Ranked causes

1. Hardware configuration change or SCSI device malfunction (occasional)
2. NPR LED display malfunction (rare)
3. Safety loop relay malfunction (occasional)
4. System shutdown failure (rare)

First check

Access Misc Test from diagnostics menu

Test point: H/W Diagnostics menu
Expected: Misc test selection window appears after selecting [Service] -> [Diagnostics & analysis] -> [H/W Diagnostics] -> [Interactive Test] -> [Misc Test]

6 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Electromagnetic interference with other equipment caution

CT system may cause EMC issues affecting connected or nearby electronic devices through air or cables

Ranked causes

1. Improper installation or cable routing (common)
2. System covers left open during operation (occasional)
3. Loose fasteners or damaged gaskets (occasional)
4. Unauthorized modifications to system (rare)

First check

Verify installation location distance from other equipment

Test point: General equipment area
Expected: Equipment positioned as far as possible from other electronic devices

5 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Positioning lights halogen horizontal alignment (right-left) caution

Inner and outer right-left lights horizontally misaligned; top light horizontal misalignment; vertical light offset from phantom surface

Ranked causes

1. Inner right-left light horizontal adjustment screw (B) out of tolerance (common)
2. Outer right-left light horizontal adjustment screw (B) out of tolerance (common)
3. Top light horizontal adjustment screw (B) out of tolerance (common)

First check

Verify inner right-left light horizontal alignment

Test point: Vertical positioning light relative to phantom surface
Expected: Vertical light and phantom surface aligned within ±0.5 mm, ±0.5 mm
Tools: Positioning lights, adjustment screw B, lever D, water phantom

2 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

CAM amplifier linearity out of specification

Detector channel response linearity fails verification during no-X-ray test scans

Ranked causes

1. Amplifier gain drift or non-linearity (occasional)
2. Detector channel response mismatch (occasional)
3. Insufficient warm-up before test (common)

First check

Verify vector file 7 linearity ratio within tolerance

Test point: View Vector plot for Vector File No. 7
Expected: 0.9995 < ratio < 1.0005

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Component ejection hazard during gantry rotation with covers removed patient safety

Risk of components or objects being ejected at high velocity when gantry rotates with side covers removed

Ranked causes

1. Side covers removed during gantry operation or rotation (common)
2. Board chassis left open during scanning (occasional)
3. Components not properly secured with correct torque (occasional)

First check

Inspect gantry side covers for removal or damage

Test point: Right and left side covers of gantry
Expected: Covers installed and secured in place

1 more check with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

DAS offset data out of specification

Offset data averages outside acceptable range without offset file correction

Ranked causes

1. Detector or DAS channel drift or malfunction (unknown)
2. Offset file correction needed (common)
3. Detector response drift after warm-up (occasional)

First check

Verify Avg of Mean of Active Views without offset correction

Test point: Fan Data Averages display
Expected: 3000 ≤ Avg of Mean ≤ 6000

3 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Electrocution hazard from 400VAC slip ring supply high voltage

Risk of electrocution when servicing X-ray generator or slip ring components due to active 400VAC supply

Ranked causes

1. XG Power Switch (400VAC) not turned OFF before service (common)
2. CB1 and CB2 circuit breakers not turned OFF (common)
3. Capacitors in XG units not discharged (occasional)

First check

Verify XG Power Switch is OFF

Test point: XG Power Switch at gantry rear base
Expected: Switch in OFF position; System Safety Loop open

2 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gantry rotates unintentionally during service patient safety

Gantry continues rotating or can rotate when it should be disabled, posing impact hazard to personnel

Ranked causes

1. Axial Drive Switch not turned OFF (common)
2. Right maintenance cover removed without reinstalling before other covers installed (occasional)
3. Service brackets not engaged when covers removed (occasional)

First check

Verify Axial Drive Enable Buzzer status

Test point: Gantry rear base
Expected: Buzzer is silent

1 more check with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gantry rotation fails during power-on test patient safety

Gantry does not rotate or rotation check terminates prematurely with ERRG LED lighting during power-on initialization

Ranked causes

1. Servo amplifier not powered (common)
2. Service switch (SW1) set to OFF (occasional)
3. Gantry azimuth counter initialization timeout (> 25 sec) (occasional)

First check

Verify service switch SW1 position on TGP board

Test point: Service switch SW1 on TGP board
Expected: Set to SYS (normal) or MNL (manual)

2 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Memory module installation and configuration incomplete

System not properly configured after installing IPU2 board and memory modules; requires MD EXT switch settings and P-ON test verification before operation

Ranked causes

1. MD EXT switch (S7A1) not set to correct configuration for kit type (common)
2. IPU2 board not installed in OC nest slot 2 (common)
3. P-ON test level 2 not run to verify system startup (common)

First check

Run P-ON test level 2 to verify system startup

Test point: CPW Board slot 1, Dip SW 8A1
Expected: Startup screen appears after approximately 14 minutes with no errors

2 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power line voltage disturbances not monitored high voltage

Input power line voltage requires monitoring for mean voltage, surges, sags, impulses, and frequency stability during installation to detect correlation with system malfunctions

Ranked causes

1. Line voltage out of specification or unstable (occasional)
2. Mean line voltage outside acceptable range (rare)
3. Line frequency drifting outside tolerance (rare)

First check

Measure current line voltage at PDU input terminals L1, L2, L3

Test point: Power Distribution Box terminals L1, L2, L3
Expected: 200/208/380/400/415/440/460/480 VAC at 50/60 Hz
Tools: Line analyzer (Dranetz 606-3 or equivalent)

3 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Software loading: Load-From-Cold (LFC) procedure

Full system software loading (OS + NP application) to system hard disk from CD-ROMs and MODs. Reinitializes all system data disks, erasing all images and scan data.

Ranked causes

1. System software update or downgrade required (common)
2. Patch software available for NP application (occasional)
3. System downgrade to older version (rare)

First check

All patient images and scan data saved to MOD

Test point: MOD optical disk
Expected: Images and raw data archived successfully

10 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Temperature environment out of specification caution

Scan room and equipment room temperature and humidity do not meet installation specifications; excessive temperature may overstress components

Ranked causes

1. Scan room temperature outside range 20–28 °C (common)
2. Equipment room temperature outside range 15–30 °C (occasional)
3. Relative humidity outside safe range (occasional)

First check

Record scan room temperature

Test point: Scan room with thermometer/recorder
Expected: 20 °C to 28 °C with at least 5 °C/hr gradient, to 28 °C
Tools: Thermometer, temperature/humidity recorder

3 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

X-ray exposure risk during improper equipment operation radiation

Potential radiation injury to operators and bystanders from inadequate shielding or lack of protective precautions during CT scanner use and maintenance

Ranked causes

1. Operator or technician not trained in radiation safety protocols (common)
2. Inadequate use of available protective materials and devices (common)
3. Unqualified personnel performing electrical or maintenance work (occasional)

First check

Verify radiation safety training credentials for all personnel

Test point: Training documentation
Expected: Current NCRP and ICRP training certification on file

2 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Abnormal gantry rotation noise or movement caution

Gantry movement is not smooth or abnormal noise detected during manual rotation

Ranked causes

1. Brush Block Assy not properly restored to original configuration (common)
2. Brush assembly installation issue (occasional)

First check

Manual gantry rotation test

Test point: Gantry
Expected: Smooth movement with no abnormal noise through at least one complete rotation

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Audio Function Test

Operator Console audio functional check including OC and table speaker tests for Auto Voice, CD player, X-ray ON buzzer, and Alert. Tests verify volume control and sound output.

Ranked causes

1. Audio output or volume control malfunction (occasional)
2. Auto Voice Playback still active (occasional)

First check

Access Audio Function Test from diagnostics menu

Test point: H/W Diagnostics menu
Expected: Audio test screen appears after selecting [Service] -> [Diagnostics & analysis] -> [H/W Diagnostics] -> [Interactive Test] -> [Audio Test]

5 more checks with pass and fail actions, 6 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Azimuth belt tension caution

Adjust axial belt tension to specified gap between tensioner components to maintain drive without over-tensioning

Ranked causes

1. Belt tension incorrect or over-tensioned (common)
2. Belt over-tensioned due to incorrect adjustment (occasional)

First check

Loosen mounting and adjustment hardware

Test point: Mounting plate bolts and set nut
Expected: All bolts and nut loose enough to allow adjustment

3 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: CAM Amplifier Linearity radiation

Check for non-linearity in detector amplification response across different tube currents. Performed after X-ray tube, detector, DAS, or CAM board replacement.

Ranked causes

1. Detector or amplifier non-linearity after component replacement (common)
2. Detector crystal response drift (occasional)

First check

Perform 100 mA air stationary scan

Test point: Offline Scan service menu
Expected: Scan 1: Azimuth 0°, Thickness 10 mm, Focus Large, KV 120, MA 100 mA

5 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Halogen positioning lights alignment patient safety

Five halogen positioning lights (inner right/left, outer right/left, outer top) must be aligned with scan center and phantom surface for accurate patient positioning

Ranked causes

1. Positioning lights misaligned vertically or horizontally (common)
2. Water phantom surface not parallel to scan plane (occasional)

First check

Place fine pin at phantom holder center and position perpendicular to scan plane

Test point: M3 hexagonal wrench at phantom holder center
Expected: Pin aligned with vertical line in magnified (x4) image

7 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Positioning lights halogen vertical alignment (right-left) caution

Inner and outer right-left positioning lights vertically misaligned with pin; horizontal light offset from pin image

Ranked causes

1. Inner right-left light vertical adjustment screw (A) out of tolerance (common)
2. Outer right-left light vertical adjustment screw (A) out of tolerance (common)

First check

Position pin perpendicular to scan plane

Test point: Pin image versus vertical reference line
Expected: Pin and vertical line aligned within ±0.5 mm, ±0.5 mm
Tools: M3 hexagonal wrench or fine pin, phantom holder, cursor/magnification tools

3 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Remove gantry front cover caution

Access to internal gantry components by removing front cover with service angles and connector management

Ranked causes

1. Front cover removal procedure for standard installation (common)
2. Front cover removal for small room (short-footprint mode) (occasional)

8 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Remove gantry side covers caution

Access to side gantry components by removing left and right side covers with connector disconnection as needed

Ranked causes

1. Left side cover removal (common)
2. Right side cover removal (common)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: RMT CNT jumper configuration

Setting JP1 jumper plug on RMT CNT (Remote Control) module according to TGP board part number and revision

Ranked causes

1. RMT CNT part 2175741 with TGP 2156510-3 or earlier (common)
2. RMT CNT part 2175741-2 or later with TGP 2156510-4 or later (common)

First check

Identify RMT CNT part number

Test point: RMT CNT module label
Expected: Part No. 2175741 or 2175741-2 or later

3 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Rotation balance caution

Achieve balance of rotating gantry assembly through rough and fine weight adjustment to minimize resistance and ensure smooth rotation

Ranked causes

1. Gantry unbalanced in CW or CCW direction (common)
2. Main weight unbalanced (common)

First check

Rough balance check with main weight at 6 o'clock

Test point: Main weight position
Expected: Gantry does not rotate on its own

3 more checks with pass and fail actions, 3 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Saving system state data

Save system configuration, preferences, calibration files, and operational data to MOD before performing software installation to enable restoration after LFC/LFW procedure.

Ranked causes

1. System state data must be preserved before software re-initialization (common)
2. Option key information needs backup (common)

First check

Verify system powered ON

Test point: Main switch of OC
Expected: System on and main screen displayed

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Emergency stop switch not accessible or not activated during emergency patient safety

Inability to stop gantry rotation quickly during emergency situation due to inaccessible or misused stop switches

Ranked causes

1. Using Stop Scan switch instead of Emergency Stop switch (common)
2. Emergency stop switches on gantry frame not connected when covers removed (occasional)

First check

Identify correct Emergency Stop switch location

Test point: Operator console or gantry
Expected: Emergency Stop Switch clearly visible and accessible (not Stop Scan switch on keyboard)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gantry rotation check not performed patient safety

Gantry mechanical rotation, absence of interference, and proper home position return must be verified before operation

Ranked causes

1. Gantry mechanical obstruction or malfunction (occasional)
2. Gantry fails to stop at home position (rare)

First check

Switch OFF Rotate switch

Test point: Gantry rear base Rotate switch
Expected: Switch in OFF position

10 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gantry tilt or table up/down relay malfunction patient safety

Relay circuit designed with dual series relays fails to properly disable pump/valve mechanism when relay should be open; relay remains closed or fails to activate on command

Ranked causes

1. Direct relay stuck closed (enable relay fails to isolate when open) (occasional)
2. Enable relay stuck closed (processor cannot command relay to open) (occasional)

First check

Activate enable relay and verify pump/valve mechanism does not operate

Test point: Gantry tilt and table up/down pump/valve mechanism
Expected: No operation; no fluid flow; no movement

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Gantry tilting hazard during service with covers loose patient safety

Risk of gantry falling or unexpected movement during tilting if covers and support mechanisms are not properly secured

Ranked causes

1. Covers not secured before tilting gantry (common)
2. Azimuth lock pin not used to hold gantry during component removal (common)

First check

Verify all gantry covers are secured

Test point: Side covers, front cover, rear cover, tube hoist rail
Expected: All covers installed, latched, and secure

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Management processor communications failure

Management processor unable to communicate with operator console or OGP board on gantry rotative frame; IMS (Intermediate Support) not responding

Ranked causes

1. Communication interface fault between management processor and console/OGP board (unknown)
2. IMS (Intermediate Support) interface fault (unknown)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Memory capacity verification required after upgrade

System memory must be validated through scanning, paging, and post-reconstruction tests to ensure proper function after memory module installation

Ranked causes

1. Memory not verified after module installation (common)
2. Post reconstruction test not completed (common)

First check

Run POST RECON test with image subtraction

Test point: Image processing, Subtraction function
Expected: Subtracted image (A.B.C;1 minus A.B.C;2) shows nil image at Window Width 2, Window Level 0

2 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

OGP ROM not verified or updated

SP ROM on OGP board requires verification of part number and potential replacement with newer version to ensure gantry operation compatibility

Ranked causes

1. OGP ROM part number is 2121676-2 or lower (outdated) (occasional)
2. OGP ROM part number is 2121676-3 or later (current) (occasional)

First check

Verify SP ROM part number on OGP board at location U15E

Test point: OGP board, location U15E
Expected: Part number 2121676-3 or later (current version) part number

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Signal brush contact failure or intermittency patient safety

Signal brushes or slip rings show poor electrical contact causing signal loss or intermittent data transmission during gantry rotation

Ranked causes

1. Brush wear below check line, reduced contact pressure (common)
2. Slip ring contamination, dust, or grease coating reducing contact (common)

First check

Perform signal brush contact voltage check on problematic ring pair

Test point: Oscilloscope measurement across 120 Ω resistor while rotating
Expected: No voltage drops greater than 0.5 V, smooth continuous signal without fluctuations, +/- 0.5 V
Tools: Digital storage oscilloscope in envelope mode, Ring Service Tool (2206131)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Software loading: Load-From-Warm (LFW) procedure

NP application loading only from CD-ROMs and MODs to system hard disk. System remains powered on. Does NOT reinitialize system data disks.

Ranked causes

1. NP application software update required (no OS change) (common)
2. NP patch software available (occasional)

First check

NP application software installation in LFW mode completed

Test point: Display after automatic reboot
Expected: IRIS main menu appears without OS reinstall

1 more check with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

X-ray generator KV stabilization and mA linearity check radiation

Verify KV and mA output remain within specification across multiple stations during functional check

Ranked causes

1. KV deviation exceeds ±5 kV specification (occasional)
2. mA deviation exceeds ±20 mA specification (occasional)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

AC/DC 3 Phase Mid Power Assembly failure high voltage

DC bus voltage loss; rectifier block malfunction; AC/DC conversion failure; board overheating or component failure

Ranked causes

1. AC/DC board electronic failure or rectifier block failure (unknown)

First check

DC bus voltage

Test point: +DC and −DC terminals on board
Expected: Correct DC voltage per system specification
Tools: DMM

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Access XG CPU board for firmware check caution

Procedural steps to safely access CPU board in electronic rack for inspection

Ranked causes

1. Routine maintenance procedure for firmware version verification (unknown)

First check

Turn Rotate, XG, Slip Ring switches OFF

Test point: Rear base of Gantry
Expected: All three switches in OFF position

4 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Aperture assembly requires replacement caution

Aperture assembly needs removal and installation with ratio check verification

Ranked causes

1. Aperture assembly wear or malfunction (unknown)

First check

Set gantry to 0° tilt and HOME position

Test point: Gantry tilt angle and position
Expected: 0° tilt, HOME position

6 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Aperture motor driver failure

Aperture motor driver not responding or not controlling aperture position

Ranked causes

1. Defective aperture motor driver assembly (common)

First check

Verify aperture motor driver response to control signals

Test point: Aperture Motor Driver Assy connectors
Expected: Aperture opens and closes smoothly in response to commands

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Audio function test - Gantry speaker Auto Voice and CD player

Verify Gantry speaker outputs Auto Voice and CD player audio with volume control

Ranked causes

1. Gantry speaker or audio output circuit failure (unknown)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Audio function test - OC speaker alert

Verify alert sound outputs once and alert width and frequency controls function

Ranked causes

1. Alert sound circuit or audio output circuit failure (unknown)

First check

Alert sound output

Test point: OC speaker
Expected: Alert sounds once when [ON] button clicked once

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Audio function test - OC speaker Auto Voice

Verify OC speaker outputs Auto Voice message and volume controls function

Ranked causes

1. OC speaker or audio output circuit failure (unknown)

First check

Auto Voice message output and volume control

Test point: OC speaker
Expected: Auto Voice message audible; volume adjustable via L and R sliders

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Audio function test - OC speaker CD player

Verify OC CD player outputs audio and volume controls function

Ranked causes

1. OC CD player or audio output circuit failure (unknown)

First check

CD player audio output and volume control

Test point: OC speaker
Expected: CD audio audible when music CD played; volume adjustable via L and R sliders

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Audio function test - OC speaker X-ray ON buzzer patient safety

Verify X-ray ON buzzer sounds and buzzer modulation and frequency controls function

Ranked causes

1. X-ray ON buzzer or audio output circuit failure (unknown)

First check

X-ray ON buzzer sound continuity

Test point: OC speaker
Expected: Buzzer sounds continuously while [ON/OFF] button is ON; stops when OFF

2 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Auto voice not heard or unintelligible patient safety

Autovoice announcements for scan start or end not heard or not understandable

Ranked causes

1. Audio output circuit malfunction or speaker failure (unknown)

First check

Listen for autovoice scan start announcement

Test point: Audio speaker output
Expected: Clear, understandable audio announcement for scan start

1 more check with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Axial drive belt requires replacement caution

Axial drive belt needs removal and installation after removing covers and setting azimuth lock pin

Ranked causes

1. Axial drive belt wear or damage (unknown)

First check

Switch OFF Rotate, XG Power, Slip Ring115V switches

Test point: Gantry rear base switches
Expected: All three switches OFF

4 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Axial scan does not complete or errors occur

Axial scan with specified parameters fails to complete without error

Ranked causes

1. DAS/Detector malfunction or X-ray generator instability (unknown)

First check

Perform axial scan with test parameters

Test point: Detector and X-ray generator during scan
Expected: Scan completes without error kV, as set

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Balun assembly requires replacement caution

Balun assembly with coil needs removal and installation with data transfer check and gantry restoration

Ranked causes

1. Balun assembly failure or coil damage (unknown)

First check

Switch OFF Rotate, XG Power, Slip Ring115V switches

Test point: Gantry rear base switches
Expected: All three switches OFF

6 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Brush block assembly misalignment caution

Brushes not centered between slip ring track barriers after installation; potential contact issues

Ranked causes

1. Brush Block Assy pin not aligned to corresponding hole (common)

First check

Visual inspection of brush position

Test point: Brush Block Assy
Expected: Brushes centered between slip ring track barriers

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Air and Phantom Calibration Sequence radiation

Automated sequential execution of Air Calibration followed by Phantom Calibration using calibration station phantoms. Establishes baseline CT number reference values. Precondition: bow-tie filter must be installed. Performed via Auto Sequence 1.

Ranked causes

1. Air and phantom calibration required after Hilight calibration or major component replacement (common)

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Air and Phantom Calibrations radiation

Establish baseline detector response for water and air reference standards. Bow-tie filter must be installed. Performed after Hilight calibrations (Q, XT, AV, DG as required). Includes Auto Sequence 1 (Air Cal → Phantom Cal).

Ranked causes

1. Detector sensitivity baseline drift after calibration-triggering component replacement or alignment (common)

First check

Verify bow-tie filter is installed on collimator

Test point: Gantry collimator assembly
Expected: Bow-tie filter present and properly seated

3 more checks with pass and fail actions, 1 corrective action, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: AV Calibration (AV-CAL) radiation

Compensate for Lumex crystal afterglow persistence following X-ray pulse cessation. Performed when detector or alignment is changed. Takes ~2 minutes. Gantry does not rotate.

Ranked causes

1. Detector afterglow (phosphorescence) from Lumex crystals after detector replacement or alignment (common)

First check

Verify X-ray tube is sufficiently cool before starting

Test point: Tube case temperature indicator
Expected: Below 10% heat level

2 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: AV-CAL (Afterglow Compensation) radiation

Create After Glow Vector file to compensate for persistent light emission from Lumex crystal after x-ray radiation stops. Gantry does not rotate during this procedure. Approximately 2 minutes duration.

Ranked causes

1. Detector afterglow artifact after detector replacement or beam-on-window alignment (common)

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Axial scan data collection parameters radiation

System collects 972 views of actual data during axial scan at view period synchronized with gantry azimuth; scan speeds vary 0.8 to 3.0 sec

Ranked causes

1. Axial scan data collection with speed-dependent view period (common)

First check

Verify correct view period for selected scan speed

Test point: Scan speed setting
Expected: 0.8 sec: 823 µsec/view; 1.0 sec: 1029 µsec/view; 1.5 sec: 1543 µsec/view; 2.0 sec: 2058 µsec/view; 3.0 sec: 3086 µsec/view
Tools: System configuration

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Calibration: Axial scan geometry and offset correction radiation

Axial scans perform 360-degree rotation collecting 972 views of data at variable scan speeds. Offset data (64 views) collected prior to x-ray exposure for correction of actual scan data.

Ranked causes

1. Offset data required for x-ray data correction (common)

First check

Verify gantry acceleration to constant scan speed

Test point: Gantry status
Expected: Gantry accelerated and at constant scan speed

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Calibration: Axial scan offset data collection radiation

System collects 64 views of offset data from DAS prior to actual x-ray exposure during axial scans to correct x-ray data

Ranked causes

1. Offset data collection required for axial scan calibration (common)

First check

Verify 64 offset data views collected

Test point: DAS offset data collection
Expected: 64 views
Tools: System monitoring

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Brush block assembly cleaning caution

Remove and clean brush block assembly and surrounding components using dry Kim wipes and HEPA vacuum cleaner to remove brush powder and metal filings. Required during periodic maintenance.

Ranked causes

1. Accumulation of brush powder and metal filings contaminates brushes and slip rings (common)

First check

Power down gantry

Test point: Gantry rear base switches
Expected: 'Rotate', 'XG Power', 'Slip Ring 115V' switches OFF

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Calibration: Brush debris cleaning caution

Remove brush powder and debris from gantry covers, rear base, slip ring cover, tracks, detector surface, and mylar ring using vacuum and dry wipes

Ranked causes

1. Brush debris and powder accumulation in gantry housing and components (common)

First check

Switch OFF safety switches

Test point: Gantry rear base
Expected: Rotate, XG Power, Slip Ring 115V switches OFF

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More symptoms

Calibration: Brush debris cleaning from gantry interior
Calibration: Brush wear inspection
Calibration: CD-ROM Drive SCSI Configuration
Calibration: Cleaning of Brush Block assy
Calibration: Cradle absolute position (in limit)
Calibration: Cradle absolute position (out limit)
Calibration: Cradle compensation (position stability vs table height)
Calibration: Cradle IN limit
Calibration: Cradle repeatability (In-to-Out-to-In)
Calibration: Cradle repeatability (Out-to-In-to-Out)
Calibration: CRT Monitor Factory Preset Reset
Calibration: CRT Monitor Horizontal Moire Reduction
Calibration: CRT monitor input port selection
Calibration: CRT Monitor Input Select
Calibration: CRT Monitor Language Selection
Calibration: CRT Monitor Manual Degaussing
Calibration: CRT Monitor User Color
Calibration: CRT monitor user color adjustment
Calibration: CRT Monitor Vertical Moire Reduction
Calibration: CRT Monitor Video Input Level
Calibration: DAS Count Check
Calibration: DASIFN Board Switch Configuration
Calibration: DC Power Supplies
Calibration: DC power supplies (+5V, +12V, -12V)
Calibration: DC power supplies on rotative frame
Calibration: DC power supplies on stationary frame
Calibration: Detector
Calibration: Detector Beam-on-Window
Calibration: DG Calibration (DG-CAL)
Calibration: DG-CAL (Scan Time Gain Correction)
Calibration: Display Japanese messages on scan screen
Calibration: Display SMPTE image
Calibration: DTRF jumper configuration
Calibration: Fan operation
Calibration: Filter center alignment and CT number
Calibration: Foot switch position adjustment
Calibration: FRONT PNL Power OFF Delay Time
Calibration: G. Pulse position
Calibration: Gantry initialize movement
Calibration: Gantry movement check
Calibration: Gantry rear base switches
Calibration: Gap between cradle and cradle support
Calibration: Gravity SAG
Calibration: Gravity SAG measurement
Calibration: Hard Disk Drive 2205368 SCSI Configuration
Calibration: Hard Disk Drive SCSI Configuration (2205368)
Calibration: Hard disk drive system software load
Calibration: Heat Soak
Calibration: Heat soak procedure
Calibration: HV Tank flat cable transfer
Calibration: IMS (Intermediate Support) position (electrical limits)
Calibration: IMS position (mechanical limits verification)
Calibration: Install gantry covers
Calibration: Install option software
Calibration: Installing NP/NP Plus application software
Calibration: Installing system software core OS
Calibration: Keyboard Function Test
Calibration: KV and MA output verification
Calibration: Laser positioning lights alignment
Calibration: Laser positioning lights alignment (NP+)
Calibration: Longitudinal accuracy (In-to-Out travel)
Calibration: Longitudinal accuracy (Out-to-In travel)
Calibration: MA check with load resistor
Calibration: Memory module (DIMM) installation verification
Calibration: MOD Drive 2194318 SCSI Configuration
Calibration: MOD Drive 2198923 SCSI Configuration
Calibration: MOD Drive SCSI Configuration (2194318)
Calibration: MOD Drive SCSI Configuration (2198923)
Calibration: Monitor Function Test
Calibration: NAA1 assembly audio function
Calibration: NAA1 Audio Board Input Impedance
Calibration: NAA1 Audio Input and Speaker Volume
Calibration: NAA1 Ground Connection
Calibration: NAA1 Speaker Volume
Calibration: NAA2 ground connection
Calibration: NAA2 input impedance
Calibration: NPR LED test
Calibration: NPRIF Board Jumper Configuration
Calibration: NPRM Board Memory and NPRS Configuration
Calibration: NPRS Board Jumper Settings
Calibration: OC power supplies (+12VDC, -12VDC, +5VDC)
Calibration: OC Power-up Sequence
Calibration: OGP DIP switches
Calibration: Operator Console jumper and switch settings
Calibration: Operator Console Power Supply Ground Connection
Calibration: Operator Console power-up sequence verification
Calibration: Parallel setting of cradle
Calibration: Patient intercom volume adjustment
Calibration: PCI Host Card Connector Configuration
Calibration: PCI Host Card Jumper Configuration
Calibration: PCI tray installation verification
Calibration: Photo sensor
Calibration: Photo sensor and plate alignment
Calibration: Plane of Rotation
Calibration: Positioning lights halogen top light right-left alignment
Calibration: Power Off Delay Time
Calibration: Powering off optional Pioneer MOD drive (LFC only)
Calibration: Q Calibration (Q-CAL)
Calibration: Q-CAL (Focus Position)
Calibration: Radial Alignment
Calibration: Rating plate attachment
Calibration: REAR CN1 Fan Alarm Enable/Disable
Calibration: REAR CN1 Intercom Minimum Volume
Calibration: REAR CN1 Safety Loop Control
Calibration: REAR CN1 Talk On Switch
Calibration: REAR CN1 TGP Communication
Calibration: Recon cycle verification
Calibration: Remove gantry rear cover
Calibration: Remove OC covers
Calibration: Remove PDU covers
Calibration: RF Shoe position and alignment
Calibration: Rotation speed
Calibration: Rotation velocity offset
Calibration: Rotational mechanism clearance
Calibration: Saving patient images to MOD
Calibration: Scout scan cradle positioning and data collection
Calibration: Scout scan data collection
Calibration: Scout scan offset data collection
Calibration: Screw tightening torque
Calibration: Serial Port Expander SCSI Configuration (ST-1800)
Calibration: Serial Port Expander ST-1800 Configuration
Calibration: Set gantry safety switches
Calibration: Signal and power brush wear inspection
Calibration: Signal brush contact verification
Calibration: Slip ring cleaning
Calibration: Slip ring cleaning for noise reduction
Calibration: Slip ring radial position
Calibration: Software installation and system configuration
Calibration: Software loading preparation
Calibration: Speaker assembly audio function
Calibration: SUB BD service switches
Calibration: System configuration
Calibration: System configuration and desktop menu
Calibration: System module LED verification
Calibration: System revision upgrade procedure
Calibration: System shutdown before OS installation
Calibration: Table board IMS jumper configuration
Calibration: Table DOWN limit
Calibration: Table positioning in right-left direction
Calibration: Table positioning right-left alignment
Calibration: TGP board DIP switches S1
Calibration: TGP board DIP switches S2
Calibration: TGP board DIP switches S3
Calibration: TGP board jumpers
Calibration: Tube Calibration
Calibration: Unlatch switches
Calibration: Workstation Default Test
Calibration: X-ray tube automatic learning
Calibration: X-ray tube DAS count verification
Calibration: X-ray tube warm-up
Calibration: XT Calibration (XT-CAL)
Calibration: XT-CAL (Crosstalk Compensation)
Capacitor assembly screws loose
Capacitor explosion hazard in gantry
Capacitor Inverter Assembly failure
Collimator filter requires replacement
Component assembly procedure: Primary coil flat cable connection
Cooling check failure – COOLING OVER LIMIT message
Cradle stops before reaching scan position
CRT monitor manual degaussing for color correction
CRT monitor reset to factory preset
DAS data transfer errors occur
Detector and collimator/filter maintenance note
DTRF assembly requires replacement
Dust filter condition not checked
Electrical hazard during gantry service
Electrocution hazard from gantry slip rings
Electromagnetic interference from other equipment affecting CT system
Electrostatic discharge damage to circuit boards
Electrostatic discharge precaution during board service
EMC Board 3 Phases failure
Emergency stop function not tested
Emergency stop switch does not halt X-ray
External landmark function malfunction
Eye damage from laser positioning light
Fan operation check
Foot pedal contact with front cover
Functional check: Table and gantry interlock
Functional check: Table and gantry panel switches
Gantry and rotor do not stop after End Exam
Gantry cannot rotate with covers removed
Gantry rotation hazard with wrong installation sequence
Hardware inventory check
HV cable (anode/cathode) failure
HV Tank replacement required
HV Tank temperature overheat condition
Initialization and safety checks before adjustment
Inverter Coils Mid Power Assembly failure
Inverter Mid Power Assembly replacement required
Keyboard function test - 103 keyboard input
Keyboard function test - input response
Keyboard function test - LED response
KV Control Board failure
Laser positioning light malfunction
Load distribution and DC supply voltage not verified
Monitor function test - color output
Monitor function test - display pattern
Move to Scan button does not blink after confirm
Nonvolatile Parameters RAM requires replacement
OC filter clogged or dirty
OGP assembly requires replacement
Operator Console power-up fails or stops during self-test
Optical fiber cable degradation
Optical fiber cable disconnection
Pause function does not stop scan at next ISD
Perform functional scan test after memory installation
Personal injury from loose clothing or jewelry during gantry servicing
Power distribution unit input voltage not verified
Power supply PS L module malfunction
Power system lockout procedure
Pre-adjustment setup: Access power supplies and speaker panel
Pre-adjustment setup: Remove operator console covers
QA phantom quality assessment check
Replace detector assembly
RF transmitter assembly requires replacement
Rotation Board High Speed requires replacement
Rotation Capacitors Set 23/23 requires replacement
Safety loop relay test and reset
Scout scan phantom diameter measurement incorrect
Scout scan tilted gantry not inhibited
SCSI test - storage device access verification
Slip ring damage from contamination
Software upgrade not installed
Stop Scan does not immediately halt
Stud bolt installation with locktite
System installation checks not completed
System shutdown test
Thermal burn hazard from X-ray tube
Top positioning light replacement
Verify main memory size after installation
Warm-up error detected
Warm-up scan does not complete
Workstation default test - Audio
Workstation default test - Monitor
Workstation default test - Mouse
X-ray generator power and gantry servo voltage not verified
X-ray ON indicator or alarm not functioning
X-ray radiation exposure during service
X-ray tube overheat protection not functioning
XG Error 371 during continuous scanning
XG ERROR 371 occurs during helical scanning

241 more symptoms with ranked causes and checks are in ServiceForge. Connect ServiceForge to your AI

Error codes

Code	Meaning	Trigger	Severity
`100xx`	External communication errors	Communication failure with external system or network	unknown
`110xx`	Thermal errors	Generator or tube temperature limit reached	warning
`30xx`	Tube spits errors	Errors generated by X-ray tube during operation	unknown
`40xx`	Rotation errors	Rotation function malfunction or failure	unknown
`50xx`	Heater errors	Heater function malfunction or failure	unknown
`60xx`	Exposure errors	HV inverter, mA measurement, or exposure control malfunction	unknown
`70xx`	Power supply errors	Low voltage supply or DC bus voltage failure	unknown
`80xx`	Hardware errors	Internal communication failure or cable fault	unknown
`90xx`	Application errors	Saved RAM corruption or software failure	unknown
`ALERT: SCSI hard error on (1,3)`	SCSI hard drive error reported on controller 1, drive 3	Occurs during OS installation on systems with DASM (Direct Attached Storage Module) until configuration setting is completed	warning
`CHANGE`	Adjustment data not stored during gantry or table adjustment	Calibration or adjustment operation fails to save data	warning
`CONERR`	FPGA Configuration error occurred	FPGA configuration fails or becomes corrupted	error
`ERRG`	Gantry rotation operation error detected	Gantry rotation fails to respond or completes incorrectly	error
`ERRM`	Processor communication or scan operation error detected	Internal processor communication failure or scan operation error occurs	error
`ERRT`	Table or tilt operation error detected	Table or gantry tilt fails to respond or completes incorrectly	error
`FECERR`	FEC encode error detected	Forward Error Correction encoding fails during data transmission	warning
`SVALM`	Servo amplifier in alarm state or AC 200V power loss	Servo amplifier detects fault or loses mains AC power supply	error
`WARM-UP ERROR`	Warm-up scan data out of acceptable range	Data collected during warm-up scan sequence falls outside specified range limits	warning
`XG ERROR 371`	Scan cancellation error in XG CPU systems	Helical scanning with 140kV/160mA/10mm or larger thickness/90 sec or longer scan time on 90 slice option systems with XG CPU firmware V3.10 or lower	error

Likely causes and actions for each code are in ServiceForge. Connect ServiceForge to your AI

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0 fixes logged by technicians through their AI, with outcomes, for this model.

ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.