Test equipment electronic loads

Agilent 6060B: troubleshooting and error codes

The ServiceForge knowledge base holds 41 documented symptoms for the Agilent 6060B, with 60 ranked causes, 110 diagnostic checks with test points and expected values, and 11 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Blank display during power-on selftest

Front panel display remains blank; no error message appears. May indicate RAM, ROM, internal timer failure, or microprocessor lockup.

Ranked causes

1. Primary microprocessor U203 RAM failure (occasional)
2. Primary microprocessor U203 ROM failure (occasional)
3. Primary microprocessor U203 internal timer failure (occasional)
4. Primary microprocessor U203 lockup (rare)

First check

Measure SA_GATE line square wave frequency

Test point: TP201-8
Expected: 10Hz (RAM failure), 100Hz (ROM failure), or 1KHz (timer failure)
Tools: Oscilloscope

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

Overpower circuit fault caution

Overpower circuit not responding correctly to input voltage/current; power limitation not activating or deactivating properly

Ranked causes

1. U7 comparator failure (occasional)
2. R123 summing resistor pack open or incorrect value (occasional)
3. RT551 temperature monitor or U327 failure (occasional)
4. +12V reference voltage low or absent (occasional)

First check

Verify +12V reference voltage present

Test point: +12V reference input
Expected: +12V ±tolerance
Tools: DMM

CC/CV control circuit malfunction high voltage

Either CC or CV loop fails to control input power stage conduction correctly; detected during S.A. mode testing

Ranked causes

1. Incorrect CC_EN or CV_EN signal logic level (common)
2. Incorrect waveforms at test points (common)
3. Input power stage, current limit, or power limit circuit interference (occasional)

First check

Enable S.A. mode and verify waveforms match Figure 3-5

Test point: TP201 and TP301
Expected: Waveforms match Figure 3-5; applicable to CC or CV mode selected

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

Error code 105-108 at power-on despite successful self-test analysis

Unit displays error 105-108 during startup even after S.A. analysis shows no faults

Ranked causes

1. IMON adjustment out of specification (occasional)
2. U309 switch malfunction (occasional)
3. DAC or amplifier fault generating incorrect waveform (rare)

First check

Verify U309 switch closure at low level test points

Test point: U309 switches (SDB0-7 data inputs and SLW signal outputs)
Expected: Switch closes when test point is at Low level; check IMON, -10V, and VMON test points per Table 3-3

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

Overall troubleshooting guidance high voltage

General introduction to troubleshooting procedures for Agilent 6060B/6063B Electronic Loads. Describes overall approach to isolate problems to functional areas, then to specific components. Mentions verification tests in Chapter 2.

Ranked causes

1. Problem not with load but associated circuit (common)
2. Component found defective (unknown)
3. Serial EEPROM chip U211 replaced (rare)

First check

Run front panel verification tests

Test point: Load functions per Chapter 2 procedures
Expected: Load passes all verification tests

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

DAC circuit malfunction or incorrect SLEW signal

SLEW signal generated by DAC circuits is not producing correct waveforms, affecting input power control circuit operation

Ranked causes

1. Incorrect SD0-7 data bus lines to readback DAC U322 (unknown)
2. Incorrect SDB0-7 data lines to main or transient DACs (unknown)

First check

Enable S.A. mode by connecting jumpers

Test point: Test headers TP201 and TP301
Expected: Jumpers connected in S.A. mode positions

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

ERROR -102 displayed: Secondary microprocessor ROM failure or missing thermistor

Secondary microprocessor U301 internal ROM test failed, or thermistor RT551 is missing or open circuit.

Ranked causes

1. Secondary microprocessor U301 ROM failure (occasional)
2. Thermistor RT551 missing or open circuit (occasional)

First check

Inspect thermistor RT551

Test point: RT551 location on main circuit board
Expected: Component present and electrically continuous

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

Incorrect slew rate waveforms or poor slew rate response

Slew circuit waveforms incorrect when slew rates programmed from front panel; slew rate does not respond as specified

Ranked causes

1. Analog switch U317 malfunction in slew circuit (common)
2. CC/CV control circuit fault (rare)

First check

Program slew rate #1 and verify waveform

Test point: Slew circuit output (Figure 3-4 bottom waveform)
Expected: Waveform matches slew rate 0.001 A/µs in Figure 3-4
Tools: Oscilloscope with delayed sweep capability

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

Incorrect slew waveforms in S.A. mode

Slew circuit test waveforms incorrect or absent in self-analysis mode

Ranked causes

1. Incorrect SDB0-7 data inputs or SLW signal outputs from U305 (common)
2. Operational amplifier or switch fault (occasional)

First check

Verify SDB0-7 data inputs and SLW signal outputs from U305

Test point: U305 pins (SDB0-7 inputs, SLW1-SLW4 outputs)
Expected: Signatures match S.A. Table 3-13 waveform specification
Tools: Oscilloscope, S.A. mode enabled

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

Input power stage malfunction high voltage

One or more of eight parallel input power stages not functioning; detected via signature analysis in S.A. mode or abnormal power output

Ranked causes

1. Defect in specific input power stage (one of eight stages) (common)
2. Failure in all input power stages simultaneously (occasional)

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

Overpower circuit active - power limiting caution

Load operating in overpower condition; power sinking capability limited by thermal or time duration threshold

Ranked causes

1. Overpower condition exists - EPU bit false (common)
2. Overpower condition exists - EPU bit true (common)

First check

Check test points and reference voltage using Table 3-3 conditions

Test point: U12 amplifier, U7 comparators, R123 summing resistor pack, +12V reference
Expected: Values per Table 3-3

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

Overvoltage (OV) condition detected high voltage

OV circuit activates to limit input voltage; overrides CC and CV control loops

Ranked causes

1. Input voltage exceeds rated voltage; OV circuit triggered correctly (common)
2. OV circuit latch failure; R64 or D18 defective (occasional)

First check

Measure inverting amplifier U12-7 output voltage as input voltage varies

Test point: U12-7 output
Expected: 0 to -10V as input varies from zero to rated input voltage

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

Calibration: Current Monitor (IMON) circuit

IMON circuit adjustment required after input power stage component replacement

Ranked causes

1. Input power stage component replaced (common)

First check

Verify IMON reading at adjustment test points

Test point: IMON adjustment test points (Figure 6-2)
Expected: 0 ±0.5 millivolts mV, ±0.5 mV
Tools: DMM

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

Calibration: EEPROM initialization

EEPROM chip U211 must be reinitialized with GP-IB address, model number and calibration constants when U211 or main PC board is replaced

Ranked causes

1. EEPROM chip U211 or main PC board replaced (occasional)

First check

Execute command CAL 1

Test point: Load interface
Expected: Turn calibration mode on

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

Calibration: EEPROM initialization after chip U211 replacement

Serial EEPROM chip U211 must be reinitialized with proper constants (GP-IB address, model number, calibration parameters) after replacement, followed by full recalibration per Operating Manual Chapter 6.

Ranked causes

1. Serial EEPROM chip U211 replaced (rare)

First check

Enable calibration mode

Test point: GP-IB command
Expected: CAL 1 executed

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

Calibration: Full recalibration after component replacement

Electronic Load requires annual recalibration and whenever specified control circuit or power stage components (U5, U6, U13, U306-308, U320-323, U325, U326, U329, U331) are replaced, per Operating Manual Chapter 6.

Ranked causes

1. Control circuit component replaced or annual calibration due (common)

First check

Refer to Operating Manual Chapter 6 for detailed calibration procedure

Test point: Operating Manual reference
Expected: Chapter 6 calibration procedure followed in full

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

Calibration: IMON circuit after input power stage component replacement

Current monitoring circuit requires adjustment after any input power stage component (Figure 6-1, sheet 6) replacement to ensure correct current measurement.

Ranked causes

1. Input power stage component replaced (common)

First check

Turn load off and prepare for measurement

Test point: Input terminals and top cover
Expected: Load powered off, terminals disconnected, cover removed

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

CC mode PARD out of specification

Periodic and random deviation (PARD) current measurement exceeds allowed rms limit during CC mode test

Ranked causes

1. Internal current control circuit noise or instability (unknown)

First check

Measure CC mode PARD rms current

Test point: Electronic Load output
Expected: 6060B: ≤4mA rms; 6063B: ≤1mA rms, RMS in range 20Hz to 10MHz
Tools: DMM, current probe

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

CC Mode PARD reading exceeds specification caution

DMM measurement of input current noise (CC mode PARD) exceeds stated limits when monitor is set to 10V and >10A

Ranked causes

1. Input circuit noise source or poor filtering (unknown)

First check

Connect test setup as shown in Figure 2-3; set power supply to 10V and >10A

Test point: Power supply terminals
Expected: 10V output with >10A capacity

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

CC Mode Power Limit circuit does not activate within timeout high voltage

When Electronic Load power limiting test is run, overpower circuit does not turn load off within three minutes or power levels do not reach expected limits

Ranked causes

1. Overpower circuit malfunction or protection threshold miscalibration (common)

First check

Connect Electronic Load and power source per Figure 2-2; turn on load with no input power and run 5 minutes

Test point: Electronic Load front panel
Expected: Load operating with zero power dissipation

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

CR Mode resistance out of specification

Calculated Electronic Load resistance values fall outside expected ranges when tested in CR Mode across low, middle, and high ohm ranges

Ranked causes

1. Resistance range calibration drift (unknown)

First check

Set up test circuit with power supply, Electronic Load, and 0.100 ohm current monitor resistor

Test point: Input terminals and monitor resistor
Expected: Circuit connected as shown in Figure 2-1

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

ERROR -101 displayed: Secondary microprocessor RAM failure

Secondary microprocessor U301 internal RAM test failed during selftest; input disabled, Err annunciator on.

Ranked causes

1. Secondary microprocessor U301 internal RAM failure (rare)

First check

Power cycle and observe error code

Test point: Front panel display
Expected: ERROR -101 appears for 2 seconds, then INPUT DOWN 1, INPUT DWN

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

ERROR -103 displayed: Secondary microprocessor timer failure

Secondary microprocessor U301 internal timer test failed during selftest; input disabled, Err annunciator on.

Ranked causes

1. Secondary microprocessor U301 internal timer failure (rare)

First check

Power cycle and observe error code

Test point: Front panel display
Expected: ERROR -103 appears for 2 seconds, then INPUT DOWN 1, INPUT DWN

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

ERROR -104 displayed: EEPROM checksum failure

EEPROM U211 checksum error detected during secondary interface selftest; input disabled, Err annunciator on.

Ranked causes

1. EEPROM U211 checksum error (occasional)

First check

Run calibration to regenerate checksum

Test point: Front panel display
Expected: ERROR -104 should not reappear after recalibration

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

ERROR -105 displayed: Main DAC high tolerance

Main DAC circuit U320/U326 zero or full scale point is above high tolerance level; input disabled.

Ranked causes

1. Main DAC circuit U320/U326 zero or full scale calibration out of high tolerance (occasional)

First check

Verify error persists

Test point: Front panel display
Expected: ERROR -105 appears at power-on

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

ERROR -106 displayed: Main DAC low tolerance

Main DAC circuit U320/U326 zero or full scale point is below low tolerance level; input disabled.

Ranked causes

1. Main DAC circuit U320/U326 zero or full scale calibration out of low tolerance (occasional)

First check

Verify error persists

Test point: Front panel display
Expected: ERROR -106 appears at power-on

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

ERROR -107 displayed: Transient DAC high tolerance

Transient DAC circuit U321/U325 zero or full scale point is above high tolerance level; input disabled.

Ranked causes

1. Transient DAC circuit U321/U325 zero or full scale calibration out of high tolerance (occasional)

First check

Verify error persists

Test point: Front panel display
Expected: ERROR -107 appears at power-on

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

ERROR -108 displayed: Transient DAC low tolerance

Transient DAC circuit U321/U325 zero or full scale point is below low tolerance level; input disabled.

Ranked causes

1. Transient DAC circuit U321/U325 zero or full scale calibration out of low tolerance (occasional)

First check

Verify error persists

Test point: Front panel display
Expected: ERROR -108 appears at power-on

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

ERROR -4 displayed for 2 seconds

Primary microprocessor read/write test to GP-IB talker/listener chip failed; input remains disabled with Err annunciator on.

Ranked causes

1. Primary microprocessor U203 read/write test to GP-IB talker/listener chip U202 failed (common)

First check

Verify error code -4 still displays

Test point: Front panel display
Expected: ERROR -330 shown when shift key + key pressed

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

ERROR -5 displayed for 2 seconds

Primary microprocessor internal trigger test failed; input remains disabled with Err annunciator on.

Ranked causes

1. Primary microprocessor U203 internal trigger circuit test failed (common)

First check

Verify error code -5 still displays

Test point: Front panel display
Expected: ERROR -330 shown when shift key + key pressed

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

ERROR UNKNOWN displayed during secondary selftest

Unknown error displayed; EEPROM may need initialization. Input disabled, Err annunciator on.

Ranked causes

1. EEPROM U211 not initialized or corrupted (rare)

First check

Attempt EEPROM reinitialization

Test point: Front panel display
Expected: Error clears after reinitialization

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

Faulty component on data bus identified

S.A. troubleshooting has isolated a problem to a specific faulty component on data lines

Ranked causes

1. Defective IC on SD0-7 or SDB0-7 bus (unknown)

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

Front panel readings do not match expected power limit test values high voltage

Electronic Load front panel shows voltage and current readings outside expected ranges during power limit test

Ranked causes

1. Metering circuit error or display malfunction (occasional)

First check

Observe and record Electronic Load front panel V and A readings during power limit test

Test point: Front panel voltage and current display
Expected: 6060B: 33V ±tolerance, 13-17A; 6063B: 45V, 7.2-10.9A

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

Overcurrent circuit malfunction high voltage

Load unable to sink current or sinkcurrent exceeds limits at specified voltage thresholds

Ranked causes

1. U8 amplifier failure or incorrect bias (unknown)

First check

Measure voltage at U8-6

Test point: U8-6
Expected: -7V at low input voltage, -0.8V at 65V input
Tools: DMM

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

Overpower circuit does not shut down load on power limit fault high voltage

Electronic Load continues to dissipate power beyond protection threshold when power limiting is exceeded

Ranked causes

1. Overpower circuit component failure or threshold miscalibration (common)

First check

Monitor load for timeout period during power limit test (step d onwards)

Test point: Electronic Load operation and shutdown response
Expected: Prot annunciator activates and load shuts down within 3 minutes

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

Overpower circuit malfunction (CC mode) high voltage

Overpower protection circuit fails to shut down load or turn off input within specified time limit during power limit test

Ranked causes

1. Overpower circuit component failure or sensor fault (rare)

First check

Verify front panel Prot annunciator illuminates during overpower condition

Test point: Front panel indicator
Expected: Prot annunciator ON when input overpower detected

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

Transient and slew circuit operation check

Verify transient operation and slew circuit rise/fall time are within specification (60-100µs at high slew rate; 1.2-2.0ms at low slew rate). If out of spec, perform transient generator or slew circuit troubleshooting.

Ranked causes

1. Slew rise time or fall time out of specification (unknown)

First check

Set test setup and power supply

Test point: Power supply output
Expected: 6060B: 10V and 10A; 6063B: 10V and 15A

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

Transient generator does not perform functions

Transient circuit fails to operate; may not switch load levels or produce HIGH control signal to DAC circuits

Ranked causes

1. Data bus or internal clock failure (common)

First check

Verify data bus signature at U310 and U311

Test point: U310, U311 SD 0-7 lines
Expected: Valid signature per Table 3-10

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

Transient generator toggle or pulse mode malfunction

Toggle or pulse mode test fails; transient circuit cannot switch modes

Ranked causes

1. Software or firmware error in toggle/pulse mode (occasional)

First check

Execute toggle mode command and verify mode switch

Test point: Front panel TRAN mode display or output
Expected: Toggle mode active; output switches between two load levels

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

Transient generator will not change frequency

TRAN ON mode fails to change frequency when FSEL inputs are programmed

Ranked causes

1. FSEL input error or logic failure (common)

First check

Verify FSEL logic levels at U316-1, 2, 3

Test point: U316 pins 1, 2, 3
Expected: Logic levels per FSEL table corresponding to desired frequency
Tools: Logic probe

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

Trigger circuit malfunction

Trigger pulses not generated or signal lines not toggling correctly during trigger circuit operation in pulse or toggle mode

Ranked causes

1. Defective gate or IC in trigger circuit (common)

First check

Verify common ground connection for logic probe measurement

Test point: TP201-4 to TP301-2
Expected: Connected

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

Error codes

Code	Meaning	Trigger	Severity
`-101`	Secondary microprocessor U301 internal RAM failure	During secondary interface selftest sequence at power-on	error
`-102`	Secondary microprocessor U301 internal ROM failure or thermistor RT551 missing/open	During secondary interface selftest sequence at power-on	error
`-103`	Secondary microprocessor U301 internal timer failure	During secondary interface selftest sequence at power-on	error
`-104`	EEPROM U211 checksum error	During secondary interface selftest sequence when EEPROM data is verified	error
`-105`	Main DAC circuit U320/U326 zero or full scale point above high tolerance	During secondary interface selftest when main DAC is calibrated and tested	error
`-106`	Main DAC circuit U320/U326 zero or full scale point below low tolerance	During secondary interface selftest when main DAC is calibrated and tested	error
`-107`	Transient DAC circuit U321/U325 zero or full scale point above high tolerance	During secondary interface selftest when transient DAC is calibrated and tested	error
`-108`	Transient DAC circuit U321/U325 zero or full scale point below low tolerance	During secondary interface selftest when transient DAC is calibrated and tested	error
`-4`	Primary microprocessor U203 read/write test to GP-IB talker/listener chip U202 failed	During primary interface selftest sequence at power-on	error
`-5`	Primary microprocessor U203 internal trigger circuit test failed	During primary interface selftest sequence at power-on, after RAM/ROM/timer pass	error
`OV (Overvoltage)`	Input voltage has exceeded the rated input voltage limit	Input voltage at terminals exceeds rated specification	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.