Test equipment and power supplies · TMDE family

Agilent E3632: troubleshooting and error codes

The ServiceForge knowledge base holds 36 documented symptoms for the Agilent E3632, with 58 ranked causes, 72 diagnostic checks with test points and expected values, and 55 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Bias supplies problems caution

Bias supply voltages out of specification or unstable

Ranked causes

1. Regulator input voltage insufficient (occasional)
2. Circuit overload pulling down bias supplies (occasional)
3. Local bias supply inactive (occasional)
4. AC oscillations on bias supplies (rare)

First check

+5V Floating bias supply voltage

Test point: U11 pin 2
Expected: +4.75 V to +5.25 V, +/-0.25 V
Tools: Digital multimeter

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Calibration: Performance verification setup high voltage

Preliminary conditions and environment checks before running calibration or performance verification tests on the E3632 power supply

Ranked causes

1. Improper ambient temperature or humidity conditions (common)
2. Excessive ambient relative humidity (common)
3. Insufficient warm-up time (common)
4. Incorrect power-line voltage selection (occasional)

First check

Verify ambient temperature is stable and within range

Test point: Calibration environment
Expected: Between 20°C and 30°C, stable

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Unit does not power on

Power supply is inoperative, no output or display function

Ranked causes

1. AC power cord not connected (common)
2. Front-panel power switch not depressed (common)
3. Power-line fuse not installed or incorrect fuse (common)
4. Incorrect power-line voltage setting (occasional)

First check

Verify AC power cord connection

Test point: AC power inlet connector
Expected: Cord securely connected to power supply and wall outlet

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

Unit is inoperative caution

Power supply does not turn on or respond to front-panel power switch

Ranked causes

1. AC power cord not connected (common)
2. Front-panel power switch not depressed (common)
3. Power-line fuse missing or incorrect (common)
4. Incorrect power-line voltage setting (occasional)

First check

Verify AC power cord connection

Test point: power cord to power supply
Expected: AC power cord connected

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OCP tripped condition cannot be cleared

OCP TRIPPED message remains on display; OCP annunciator continues blinking; output current remains at zero

Ranked causes

1. External voltage source connected to output (occasional)
2. Output current level still above OCP trip point (common)
3. OCP trip level set too low (occasional)

First check

Inspect output terminals for external voltage source

Test point: Output connectors on rear panel
Expected: No external voltage source connected

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Power supply fails self-test

Unit does not pass internal self-test diagnostic during startup

Ranked causes

1. Incorrect power-line voltage selected (common)
2. Load connections present during self-test (common)
3. Terminal connections not fully removed during self-test (occasional)

First check

Verify power-line voltage setting is correct

Test point: Power supply rear panel voltage selector
Expected: Voltage setting matches AC input voltage

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

Power supply not ready for use high voltage

Power supply requires initial setup verification before operation including voltage settings and fuse installation

Ranked causes

1. Incorrect power-line voltage setting (common)
2. Incorrect or missing power-line fuse (common)
3. Missing supplied items (rare)

First check

Verify all supplied items received

Test point: Delivery package
Expected: Power cord, User's Guide, Service Guide, Certificate of Calibration

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Unit fails self-test

Unit fails internal self-test upon startup or manual execution

Ranked causes

1. Incorrect power-line voltage setting (common)
2. Terminal connections present during self-test (common)
3. DAC U21 failure on top board (occasional)

First check

Verify correct power-line voltage setting

Test point: voltage selector switch
Expected: Matches input voltage

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Overcurrent protection not activated

OCP circuit does not trip when output current reaches trip level; OCP annunciator does not blink; OCP menu does not show programmed level

Ranked causes

1. OCP circuit not enabled after setting trip level (common)
2. Incorrect OCP trip level set (occasional)

First check

Verify OCP annunciator status after enabling

Test point: OCP annunciator on front panel
Expected: OCP annunciator turns on

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Unit reports errors 740 to 750

Unit displays error codes 740 to 750 during operation or startup

Ranked causes

1. Power interrupted during calibration (occasional)
2. Hardware failure (occasional)

First check

Power cycle and recalibrate

Test point: unit state
Expected: Unit recalibrated and error cleared

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A/D slope convergence failed

Unit fails self-test 604. ADC integrator does not produce balanced positive and negative slope decisions during 20 ms measurement interval.

Ranked causes

1. ADC integrator slope decisions not balanced within ±10% (unknown)

First check

Observe self-test error 604 during complete self-test

Test point: Self-test readout
Expected: No error 604 displayed

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A/D sync interrupt not recognized

Unit fails self-test 603. A/D converter sync pulse times out; measurement hardware may be non-functional.

Ranked causes

1. A/D sync interrupt timeout in ADC slope counter latching (unknown)

First check

Observe self-test error 603 during complete self-test

Test point: Self-test readout
Expected: No error 603 displayed

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Calibration: Front panel voltage measurement setup

Direct measurement of dc voltage at front panel output terminals for performance verification and testing

Ranked causes

1. Need accurate voltage measurement at specified test points (common)

First check

Measure output voltage at front panel terminals

Test point: Front panel (+) and (-) output terminals
Expected: DC voltage measured directly between (+) and (-) terminals

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Calibration: Load regulation, peak-to-peak voltage, and transient response measurement

Measuring device connection technique to avoid lead impedance errors and mutual coupling effects that can invalidate measurements on power supply output

Ranked causes

1. Lead impedance affecting measurement accuracy (common)

First check

Verify measuring device connection method

Test point: Front panel output terminals at (+) and (-) terminals
Expected: Measuring devices connected through hole in neck of binding post at (A) with separate lead pairs

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Calibration: Output current

Establish current output accuracy at low (0.199A), middle (3.499A), and high (6.899A) points using 0.01Ω shunt

Ranked causes

1. Output current drift requiring recalibration (common)

First check

Measure current at low calibration point

Test point: Across 0.01Ω shunt
Expected: 0.199 A, per DVM reading
Tools: DVM, 0.01Ω shunt

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Calibration: Output current measurement setup

Four-terminal current monitoring resistor connection to eliminate voltage drop errors in load current measurement

Ranked causes

1. Voltage drops in leads and connections causing current measurement error (common)

First check

Verify current monitoring resistor connection

Test point: Current monitoring resistor (RM) monitoring points
Expected: Current-monitoring leads connected inside the load-lead connections directly at monitoring points on resistor element

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Calibration: Output voltage

Establish voltage output accuracy at low (0.45V), middle (15V), and high (29.5V) points after 1-hour warm-up

Ranked causes

1. Output voltage drift requiring recalibration (common)

First check

Measure voltage at low calibration point

Test point: Output terminals
Expected: 0.4500 V, per DVM
Tools: DVM

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Calibration: Overcurrent protection

Establish OCP threshold after current calibration

Ranked causes

1. OCP threshold drift (occasional)

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Calibration: Overvoltage protection

Establish OVP threshold after voltage calibration

Ranked causes

1. OVP threshold drift (occasional)

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Calibration: Security code entry

Power supply is factory-secured with security code. Technician must unsecure it by entering correct code before performing any calibration procedures from front panel.

Ranked causes

1. Power supply shipped with factory security enabled (common)

First check

Turn on front-panel calibration mode

Test point: Calibrate key
Expected: Beep heard after ~5 seconds, CAL MODE message displayed

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Calibration: Security code reset via internal jumper caution

When security code is forgotten, technician must open the instrument, apply a jumper to JP5 pad, and enter a new security code in calibration mode.

Ranked causes

1. Security code forgotten; cannot enter calibration mode (occasional)

First check

Disconnect power and load connections

Test point: Power cord and front terminals
Expected: All connections removed

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Cannot calibrate rundown gain

Unit fails self-test 605. Gain calibration procedure cannot complete due to hardware failure.

Ranked causes

1. Hardware failure prevents rundown gain calibration (unknown)

First check

Run complete self-test and observe error 605

Test point: Self-test readout
Expected: No error 605 displayed

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

Failure of bias supplies

Bias supplies fail causing system malfunction or self-test failure

Ranked causes

1. Bias supply component failure (unknown)

Fan test failed caution

Unit fails self-test 630. Fan current not detected. Unit beeps and error annunciator illuminates if detected at power-on. May induce overtemperature condition.

Ranked causes

1. Fan motor not running; no current flow detected (common)

First check

Measure fan motor current during power-on self-test

Test point: Fan motor power leads
Expected: Fan current flowing; fan running

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Hardware test failed

Unit fails self-test 632. Voltage or current error amplifiers are not operational. Unit beeps and error annunciator illuminates if detected at power-on.

Ranked causes

1. Voltage or current error amplifiers not operational (unknown)

First check

Observe self-test error 632 at power-on self-test

Test point: Self-test readout
Expected: No error 632 displayed; both amplifiers operational

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

I/O processor did not respond

Unit fails self-test 625. Communication not established between U17 and I/O processor U4 via optically isolated serial link. Unit beeps and error annunciator illuminates if detected at power-on.

Ranked causes

1. Serial communication failed between U17 and U4 via optical isolators U6 and U7 (unknown)

First check

Observe self-test error 625 at power-on self-test

Test point: Optical isolator serial link U6-U7
Expected: Bidirectional communication established

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I/O processor failed self-test

Unit fails self-test 626. Earth-referenced processor U4 failed internal RAM test.

Ranked causes

1. U4 processor internal RAM failure (unknown)

First check

Observe self-test error 626 during complete self-test

Test point: Self-test readout
Expected: No error 626 displayed

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

Power supply crosses over to constant voltage mode

During CC operation, if load change causes voltage limit to be exceeded, supply automatically switches to constant voltage mode and output current drops

Ranked causes

1. Load change causes voltage limit to be exceeded (occasional)

First check

Monitor CV annunciator during load change

Test point: CV and CC annunciators
Expected: CV annunciator lights when voltage limit exceeded

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Power supply does not respond to front panel key input

Front panel keys are unresponsive; unit may beep twice at power-on. Cannot establish communication between main and front panel controllers.

Ranked causes

1. Main controller U17 serial communication with front panel controller U7 failed (unknown)

First check

Verify front panel display segments light during power-on self-test

Test point: Front panel display
Expected: All segments on

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Power supply not operating in constant voltage mode

CV annunciator not lit; CC annunciator lit instead, indicating constant current mode is active

Ranked causes

1. Current limit set too low for load (common)

First check

Verify CV annunciator is lit

Test point: Front panel annunciator display
Expected: CV annunciator lit; CC annunciator off

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

RAM read/write failed

Unit fails self-test 602 during power-on or complete self-test. Error only readable from remote interface.

Ranked causes

1. RAM U14 cannot store or retrieve data correctly (unknown)

First check

Observe self-test error 602 during power-on or complete self-test

Test point: Self-test readout
Expected: No error 602 displayed

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

Rundown gain out of range

Unit fails self-test 606. Nominal gain between integrating ADC and U17 on-chip ADC is outside ±10% tolerance.

Ranked causes

1. ADC gain outside nominal ±10% tolerance range (unknown)

First check

Observe self-test error 606 during complete self-test

Test point: Self-test readout
Expected: No error 606 displayed; gain within ±10%, ±10%

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Rundown gain too noisy

Unit fails self-test 607. Gain repeatability test shows noise exceeding ±64 LSB on U17 on-chip ADC.

Ranked causes

1. ADC gain noise exceeds ±64 LSB over eight measurements (unknown)

First check

Observe self-test error 607 during complete self-test

Test point: Self-test readout
Expected: No error 607 displayed; gain noise <±64 LSB, <±64 LSB

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

Serial configuration readback failed

Unit fails self-test 608. Last 3 bytes of serial configuration data do not match when clocked back through U22.

Ranked causes

1. Serial data path through U22 corrupts configuration data (unknown)

First check

Observe self-test error 608 during complete self-test

Test point: Self-test readout
Expected: No error 608 displayed; configuration readback matches original

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System DAC test failed

Unit fails self-test 631. DAC hardware is non-functional. Digital readback of DAC output is outside valid range.

Ranked causes

1. Digital-to-Analog Converter hardware not operational (unknown)

First check

Observe self-test error 631 during complete self-test

Test point: Self-test readout
Expected: No error 631 displayed; DAC readback within valid range

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

Unable to sense line frequency

Unit fails self-test 624. LSENCE logic input on U17 is not toggling. Unit assumes 50 Hz line operation thereafter.

Ranked causes

1. LSENCE logic input U17 not toggling; line frequency detection failed (unknown)

First check

Observe self-test error 624 during power-on self-test

Test point: LSENCE logic input at U17
Expected: Logic signal toggling at mains frequency

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

Error codes

Code	Meaning	Trigger	Severity
`-330`	Self-test failed	Self-test execution during power-up or calibration	critical
`-350`	Too many errors	Multiple error conditions detected	critical
`501`	Isolator UART framing error	Serial communication with isolator module	error
`502`	Isolator UART overrun error	Data buffer overflow in isolator communication	error
`511`	RS-232 framing error	RS-232 communication during command reception	error
`512`	RS-232 overrun error	RS-232 receive buffer overflow	error
`513`	RS-232 parity error	Parity check fails during RS-232 reception	error
`514`	Command allowed only with RS-232	Command issued without RS-232 interface active	warning
`521`	Input buffer overflow	Input command buffer exceeds capacity	error
`522`	Output buffer overflow	Output data buffer exceeds capacity	error
`550`	Command not allowed in local	Remote command attempted in local mode	warning
`601`	Front panel communication failed	Power-on or complete self-test; main controller U17 cannot establish serial communication with front panel controller U7	error
`602`	RAM read/write error	Power-on or complete self-test; RAM U14 cannot correctly store and retrieve 55h and AAh patterns	error
`603`	A/D converter sync timeout	Power-on or complete self-test; A/D sync interrupt not recognized; timeout occurs	error
`604`	A/D slope convergence out of range	Power-on or complete self-test; ADC integrator slope decisions not balanced within ±10%	error
`605`	Rundown gain calibration failed	Power-on or complete self-test; gain calibration procedure cannot complete	error
`605`	Cannot calibrate rundown gain	Rundown gain calibration step	error
`606`	Rundown gain out of tolerance	Power-on or complete self-test; nominal gain between integrating ADC and U17 on-chip ADC outside ±10%	warning
`607`	Rundown gain repeatability failed	Power-on or complete self-test; ADC gain noise exceeds ±64 LSB over eight measurements	warning
`607`	Rundown too noisy	Rundown signal noise measurement	warning
`608`	Serial configuration data corruption	Power-on or complete self-test; last 3 bytes of configuration data do not match on readback	error
`624`	Line frequency detection failed	Power-on or complete self-test; LSENCE logic input at U17 not toggling	warning
`624`	Unable to sense line frequency	Line frequency detection during startup	critical
`625`	I/O processor communication failed	Power-on or complete self-test; bidirectional communication not established between U17 and I/O processor U4	error
`626`	I/O processor RAM test failed	Power-on or complete self-test; earth-referenced processor U4 internal RAM test fails	error
`630`	Fan motor not running	Power-on or complete self-test; fan current not detected	critical
`630`	Fan test failed	Cooling fan operation test	critical
`631`	System DAC not operational	Power-on or complete self-test; DAC readback data outside valid range	error
`632`	Power circuit error amplifier fault	Power-on or complete self-test; voltage or current error amplifiers not operational	critical
`632`	Hardware test failed	General hardware diagnostic test	critical
`701`	Cal security disabled by jumper	Calibration security check at startup	warning
`702`	Cal secured	Attempt to access calibration without authorization	warning
`703`	Invalid secure code	Incorrect code entry during calibration unlock	warning
`704`	Secure code too long	Secure code entry exceeding maximum length	warning
`705`	Cal aborted	Calibration procedure manually stopped or interrupted	warning
`708`	Cal output disabled	Attempt to perform calibration with output disabled	error
`712`	Bad DAC cal data	DAC calibration data checksum or validity check	error
`713`	Bad readback cal data	Readback measurement calibration data validation	error
`714`	Bad OVP cal data	Over-voltage protection calibration data check	error
`715`	Bad OCP cal data	Over-current protection calibration data validation	error
`716`	Bad OVP DNL error correction data	OVP differential nonlinearity correction data check	error
`717`	Cal OVP or OCP status enabled	Attempt calibration with OVP or OCP protection active	error
`740`	Cal checksum failed, secure state	Security state data integrity check	error
`741`	Cal checksum failed, string data	String data (labels, messages) checksum verification	error
`742`	Cal checksum failed, store/recall data in location 0	Store/recall memory location 0 checksum validation	error
`743`	Cal checksum failed, store/recall data in location 1	Store/recall memory location 1 checksum validation	error
`744`	Cal checksum failed, store/recall data in location 2	Store/recall memory location 2 checksum validation	error
`745`	Cal checksum failed, store/recall data in location 3	Store/recall memory location 3 checksum validation	error
`746`	Cal checksum failed, DAC cal constants	DAC calibration coefficient checksum validation	critical
`747`	Cal checksum failed, readback cal constants	Readback calibration coefficient checksum check	critical
`748`	Cal checksum failed, GPIB address	GPIB address configuration data checksum validation	warning
`749`	Cal checksum failed, internal data	General internal configuration data checksum check	critical
`750`	Cal checksum failed, DAC DNL error correction data	DAC differential nonlinearity correction data validation	critical
`ERROR`	Error detected during output checkout procedures	Malfunction detected during current rating verification	error
`OCP TRIPPED`	Overcurrent protection circuit has been activated due to output current exceeding the programmed trip level	Output current reaches or exceeds the OCP trip level set by the user	warning

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.