Electrosurgical units · Harmonic family

Ethicon Harmonic Generator 300: troubleshooting and error codes

The ServiceForge knowledge base holds 29 documented symptoms for the Ethicon Harmonic Generator 300, with 55 ranked causes, 63 diagnostic checks with test points and expected values, and 71 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Hand piece error

Hand piece not responding or test fails; system displays hand piece error code.

Ranked causes

1. Hand piece connector not fully inserted or misaligned (common)
2. Instrument not tightened or tissue accumulated in distal end (common)
3. Blade wrench worn or cracked (occasional)
4. Hand piece connector mechanical issue or internal fault (occasional)
5. Test tip defective (occasional)
6. Instrument defective or incompatible (occasional)

First check

Verify hand piece connector alignment and insertion

Test point: Hand piece connector and front panel alignment marks
Expected: White dot on hand piece aligned with white dot on front panel; connector fully seated

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

Footswitch activation not functioning properly

Footswitch does not respond or activate properly during operation

Ranked causes

1. Ready LED not lit on front panel (common)
2. Incorrect resistance at footswitch connectors J12 or J13 (occasional)
3. Incorrect voltage at footswitch connectors J12 or J13 (occasional)
4. Footswitch cable damaged or disconnected (occasional)
5. Generator PCB failure (rare)

First check

Is Ready LED lit on front panel?

Test point: Front panel Ready LED
Expected: LED lit

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

No tone when system is activated

No audible tone produced when attempting to activate system with foot or hand switch

Ranked causes

1. Foot switch not fully connected (common)
2. Faulty foot switch (common)
3. Hand switching adaptor not connected (occasional)
4. Faulty hand switching adaptor (occasional)
5. Hand activation not enabled (occasional)

First check

Foot switch connection

Test point: foot switch connector
Expected: Fully seated and connected

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

Hand piece temperature exceeds operating limit caution

Error Code 4 displayed; hand piece overheat condition prevents operation; may require switching to alternate hand piece.

Ranked causes

1. Hand piece still warm from recent steam sterilization (common)
2. Instrument not tightened properly or tissue debris in distal shaft (occasional)
3. Hand piece or test tip defect (rare)
4. Persistent hand piece or transducer issue (rare)

First check

Verify hand piece temperature and recent sterilization history

Test point: Hand piece exterior surface
Expected: Visually confirm recent steam sterilization cycle completed; hand piece warm to touch

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

Generator overheating caution

Generator over-temperature error code displayed; system may shut down or thermal protection activated.

Ranked causes

1. Air vents blocked by obstruction or external heat source (common)
2. Transient thermal condition or initial warm-up (occasional)
3. Generator internal thermal sensor or cooling system failure (rare)

First check

Inspect air vents for obstruction

Test point: Generator bottom and back panels
Expected: No obstructions visible; air vents clear

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

Instrument error persists after tightening patient safety

Error Code 5 continues to display even after instrument is tightened and cleaned

Ranked causes

1. Hand piece failure (occasional)
2. Test tip failure (occasional)
3. Instrument failure (occasional)

First check

Install test tip and run diagnostic

Test point: TEST button and error display
Expected: No error code displayed with test tip attached

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

Alert three-tone sequence during activation

Three-tone alarm sequence sounds when attempting to activate system

Ranked causes

1. Generator in Standby mode (common)
2. Multiple activation switches recognized simultaneously (occasional)

First check

Generator mode status

Test point: generator control panel
Expected: Ready mode (not Standby)

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

Constant tone during activation patient safety

Single continuous tone produced during system activation without stopping

Ranked causes

1. Instrument in contact with excessive tissue (common)
2. Hand piece and/or blade fault (occasional)

First check

Tissue contact on instrument

Test point: instrument distal end
Expected: No excessive tissue contact

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

Display is not working

LCD shows distorted graphics, no display, unreadable characters, or random characters upon power-up

Ranked causes

1. Random characters on startup that clear with proper function (occasional)
2. Other display issues (distorted, blank, unreadable) (occasional)

First check

Observe display immediately upon power-up

Test point: LCD display during startup
Expected: Clear display or briefly random characters that clear within seconds

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

Error Code 1: Generator caution

Error Code 1 displayed on LCD with alarm indicator and faulty generator component flashing on graphic display

Ranked causes

1. Front panel button activated during power-up sequence (common)
2. Generator functional problem (occasional)

First check

Power cycle generator

Test point: main power switch
Expected: Error Code 1 clears after power cycle

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

Unit will not power up

Unit does not power on; cooling fan, LCD, front bezel, and audible indicators are all non-functional

Ranked causes

1. Power supply not delivering power to Generator PCB (common)
2. Generator PCB defective (occasional)

First check

Verify AC power input to unit

Test point: Power cord and AC inlet
Expected: AC power present at unit inlet

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

Verify Hand Piece Assembly Receptacle continuity caution

Test continuity of wires between Hand Piece Receptacle on front panel and Generator Board wire harness connectors at J3 and J4 to detect open circuits or connection faults

Ranked causes

1. Wire open or disconnected between receptacle and J3/J4 connectors (occasional)
2. Receptacle pins worn, corroded, or loose (occasional)

First check

Power down the unit and remove the power cord

Test point: Power switch and power cord connector
Expected: Unit powered off; cord disconnected from mains

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

Activation brief pulses tone

Generator produces brief pulse tones during activation; MIN and MAX power have unique tones

Ranked causes

1. Normal system operation (common)

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

Alarm two-tone sequence caution

Two-tone alarm sequence sounds indicating component or system problem; cycles on for 3 seconds then off for 30 seconds

Ranked causes

1. Component or system fault (common)

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

Buttons are illuminated simultaneously

Two buttons or indicators that should not be illuminated at the same time are both lit (e.g., Standby and Ready buttons together)

Ranked causes

1. Front bezel circuit or LED driver failure (rare)

First check

Verify which buttons/indicators are abnormally illuminated

Test point: All front bezel button and indicator lights
Expected: Only appropriate buttons/indicators are lit for current mode

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

Buttons on Front Bezel are not responding

Unit does not respond when front bezel buttons are pressed

Ranked causes

1. Front bezel switch or button circuit failure (rare)

First check

Test each front bezel button for responsiveness

Test point: Each bezel button
Expected: Button press registers and produces menu/function change

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

Calibration: Write current level caution

Periodic calibration of the Harmonic Generator 300 output current at level 3 activation, performed every 12 months per hospital procedures to verify accuracy.

Ranked causes

1. Routine calibration maintenance required (common)

First check

Remove generator cover and connect switching and handpiece assembly

Test point: Generator cover, foot switch or hand adapter, handpiece
Expected: Assemblies connected and test tip attached with torque wrench

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

Cooling Fan is not working caution

Cooling fan is not operating even though unit is functioning normally

Ranked causes

1. Cooling fan motor failure or power loss to fan (occasional)

First check

Listen for and observe cooling fan operation during unit runtime

Test point: Fan motor and air flow
Expected: Fan rotates and produces audible cooling air flow

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

Display does not light up

LCD backlight is not functioning but LCD is displaying characters correctly

Ranked causes

1. Backlight circuit failure or lamp failure (occasional)

First check

Verify LCD characters are visible without backlight

Test point: LCD display
Expected: Characters visible but not illuminated

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

Foot switch stuck in ON position caution

System indicates foot pedal is held in activated position; unit displays Error Code 6

Ranked causes

1. Foot switch pedal stuck or contacts dirty/wet (common)

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

Front Bezel buttons or indicators are not illuminated

Buttons or indicator lights on front bezel are not illuminated during power-up or normal operation as expected

Ranked causes

1. Front bezel LED or indicator circuit failure (rare)

First check

Observe front bezel indicators during power-up

Test point: All front bezel buttons and indicator lights
Expected: All buttons and indicators illuminate as designed during startup

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

Generator Calibration Two

Second required calibration sub-process for Harmonic Generator 300, executed after Calibration One completion.

Ranked causes

1. Calibration Two procedure required (unknown)

Generator error displays on each power-up

Error Code 1:Generator error appears every time unit is powered up

Ranked causes

1. Various hardware faults logged in error memory (unknown)

First check

Enter Developer/BME mode to access error log

Test point: STANDBY and DOWN arrow buttons during power-up
Expected: Display shows error log page 1 with last 10 generator faults

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

Hand piece over-temperature error patient safety

Generator displays over-temperature error code on hand piece; system may not activate or operate normally

Ranked causes

1. Hand piece parameter out of date or temperature calibration drift (common)

First check

Verify hand piece has stabilized to room temperature

Test point: Hand piece internal temperature sensor
Expected: Temperature stable at room temperature

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

Hand piece pre-run test failure

Pre-run self-test fails; instrument not in correct state for surgery.

Ranked causes

1. Instrument in contact with objects during pre-run test (common)

First check

Verify instrument positioning during pre-run test

Test point: Instrument location and orientation
Expected: Instrument in air, not in contact with objects or tissue

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

Instrument error code 5 patient safety

Generator displays Error Code 5 indicating problem with instrument; system may not activate or pre-run test fails

Ranked causes

1. Instrument not tightened properly (common)

First check

Verify instrument connection and sheath integrity

Test point: Instrument shaft distal end and connection interface
Expected: Instrument firmly seated, no tissue debris visible

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

No tone during power-up

Generator fails to produce audible tone when powered on

Ranked causes

1. Generator failure (common)

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

Prolonged solid tone during activation exceeds 10 seconds

Continuous audible tone lasting longer than 10 seconds during system activation

Ranked causes

1. Hand piece and/or blade fault (common)

First check

Hand piece and blade fault detection

Test point: hand piece and blade
Expected: No fault indicated by TEST function

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

Unit shuts down immediately after turning on power switch high voltage

Unit powers on momentarily then immediately shuts down without full startup

Ranked causes

1. Internal short circuit activating power supply overload protection (common)

First check

Inspect for visible signs of internal short or damaged components

Test point: Generator PCB and power supply area
Expected: No visible burns, melting, or damaged components

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

Error codes

Code	Meaning	Trigger	Severity
`09`	FS1 SHORTED, FS1 PRESENT	Foot switch 1 short circuit with switch present.	error
`0A`	FS2 SHORTED, FS2 PRESENT	Foot switch 2 short circuit with switch present.	error
`0B`	FS1 SHORTED, FS1 NOT PRESENT	Foot switch 1 short circuit detected but switch not connected.	error
`0C`	FS2 SHORTED, FS2 NOT PRESENT	Foot switch 2 short circuit detected but switch not connected.	error
`10`	FS2 SHORTED, FS2 PRESENT	Foot switch 2 short circuit with switch present.	error
`11`	HP ACTIVATION SWITCH SHORTED	Handpiece activation switch short circuit detected.	error
`16`	FET_SOA_FAULT	Field-effect transistor operating outside safe operating area	error
`17`	GUNKED BLADE #329	Handpiece blade 329 contaminated or gunked.	warning
`18`	MULTI-LEVEL GUNK BLADE #279	Multi-level contamination detected on blade 279.	warning
`19`	HP WITH LOOSE BLADE/STUD #257	Handpiece blade or stud 257 loose.	error
`1A`	HP TESTED W/O BLADE #258	Handpiece tested without blade 258 attached.	warning
`1B`	HP WITH BAD BLADE #262	Handpiece with defective blade 262 detected.	error
`1C`	PRE RUN ATTACHMENT #291	Pre-run attachment failure 291 detected.	error
`1D`	PRE-RUN BROKEN BLADE #284	Blade 284 broken detected during pre-run.	error
`1E`	RUN BROKEN BLADE #320	Blade 320 broken detected during operation.	error
`1F`	LUMPED PARMS GENERIC #283	Lumped parameter generic fault 283 detected.	error
`2`	Generator overheating	Generator temperature exceeds safe operating threshold	warning
`20`	MULTI_LEVEL_FAULT_281	Multiple level detection circuit malfunction	error
`22`	GENERIC_PRERUN_FAULT	Generic prerun diagnostic failed	error
`2E`	HP DATA FAULT	Handpiece data communication fault.	error
`2F`	HP NOT PRESENT FAULT	Handpiece not connected or detected.	error
`3`	Hand piece error	Hand piece connector malfunction, instrument issue, or test failure	error
`38`	PRESENT NOT HP FAULT	Connected device is not a valid handpiece.	error
`39`	NON EES HP FAULT	Non-EES handpiece connected.	error
`3A`	UNAUTHORIZED HP FAULT	Unauthorized handpiece detected.	error
`3B`	INVALID HP PARM FAULT	Handpiece parameter invalid.	error
`3C`	HP PRESENT, FETS NOT BIASED	Handpiece connected but FETs not properly biased.	error
`3D`	OFF-RES C0 MEAS. FAULT	Off-resonance C0 measurement fault.	error
`4`	Hand piece temperature exceeded	Hand piece temperature sensor detects temperature above operating limit specification	error
`4C`	PRE RUN TRANSVERSAL #324	Pre-run transversal test failure 324.	error
`4D`	HIGH C0 RATE OF CHANGE #293	Capacitance rate of change exceeds limit 293.	warning
`4E`	HP END OF LIFE #292	Handpiece end of life reached 292.	warning
`4F`	BAD HP WITH TEST TIP #258	Defective handpiece with test tip 258.	error
`5`	Instrument error	Instrument not properly seated, tissue in distal end, hand piece issue, or defective test tip	error
`50`	UNSTABLE OUTPUT HP OPEN FAULT	Unstable output with handpiece open circuit.	error
`51`	HP SHORTED FAULT #253	Handpiece short circuit detected 253.	error
`52`	HP OPEN FAULT #254	Handpiece open circuit detected 254.	error
`53`	RUN STATE HP SHORTED	Handpiece short circuit during operation.	critical
`6`	Foot Switch error	Foot switch pedal stuck in ON position	error
`65`	HANDPIECE HIGH TEMP (AT-RES)	Handpiece temperature at resonance exceeds limit.	warning
`66`	HANDPIECE HIGH TEMP #319	Handpiece temperature exceeds limit 319.	warning
`6F`	HEATSINK HIGH TEMP FAULT	Generator heatsink temperature exceeds limit.	error
`70`	PCB_OVERTEMP_FAULT	PCB temperature exceeded safe operating threshold	error
`97`	ADC_FAILURE	Analog-to-digital converter circuit malfunction	error
`98`	FET_BIAS_FAILURE	FET bias circuit malfunction	error
`99`	HANDPIECE ID FAILURE	Handpiece ID communication failure.	critical
`9A`	SCI_FAILURE	Serial communications interface malfunction	error
`9B`	BEZEL_SWITCH_STUCK_FAILURE	Front bezel switch stuck in pressed or released position	warning
`9C`	EE_FAILURE	Electrically erasable programmable read-only memory failure	error
`9D`	EE_TIMEOUT_FAILURE	EEPROM access timeout during read/write operation	error
`9E`	AUD_TIMEOUT_FAILURE	Audio subsystem timeout during initialization or operation	warning
`9F`	WATCHDOG_FAILURE	Software watchdog timer not responding within timeout period	critical
`A0`	NMI_ISR_FAILURE	Non-maskable interrupt service routine failure	critical
`A1`	PHANTOM_ISR_FAILURE	Unexpected interrupt service routine execution	error
`A2`	ROM_CRC_FAILURE	Read-only memory checksum verification failed	critical
`A3`	DATA_MEM_FAILURE	Data memory (RAM) checksum or test failed	critical
`A4`	DSP_CORE_FAILURE	Digital signal processor core malfunction	critical
`A5`	DISPLAY_FAILURE	Display driver or display controller malfunction	error
`A6`	POWER_SUPPLY_FAILURE	Power supply voltage out of specification or power delivery failed	critical
`A7`	SOFTWARE_INT_FAILURE	Software initialization sequence failed	critical
`A8`	MITIGATION FAILURE	Mitigation circuit failure.	critical
`A9`	STR_VAL_OUT_OF_BOUNDS_FAILURE	Stored value (parameter) outside acceptable range	error
`AA`	UNKNOWN_FAILURE	Unidentified or undocumented fault condition	error
`AB`	OVERCURRENT_FAILURE	Output or supply current exceeded safe threshold	error
`AC`	ILLEGAL_ADDR_FAILURE	Illegal memory address access attempt	critical
`AD`	SPI_FAILURE	Serial Peripheral Interface bus malfunction	error
`AE`	AUDIO_FAILURE	Audio amplifier or audio circuit malfunction	warning
`AF`	STACK_FAILURE	Software stack overflow or corruption	critical
`B0`	VLVL_MITIGATION_FAILURE	Voltage level mitigation circuit failure	error
`Error Code 1`	Generator failure or front panel button activated during power-up	Functional problem with generator or accidental front panel button press during system startup	error
`Error Code #1`	Improper button sequence during generator startup	Standby and Min Power-down buttons not continuously pressed simultaneously during power-on until BME display page 1 and Standby indicator appear	error

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

Community

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.