Fluke 5720A 3109 A15 HV +DC Preamplifier Fault, 3110 A15 HV +DC Series Pass & Current Fault

Troubleshooting 5

Interpreting Diagnostic Fault Codes

3109 A15: HV +DC Preamplifier Fault

The instrument is set to the dc 1100V range with the amplitude set to 220V, 600V, and 1100V. The output of the DC HV AMPLIFIER/AC SENSE BUFFER circuit of the High Voltage/High Current assembly is measured for 0.55V ±0.2V. This voltage is divided to create HV MUX2 which is routed to Diagnostic circuit on the High Voltage Control assembly where it is connected to the SDL line for measurement by the adc circuit on the DAC assembly.

3110 A15: HV +DC Series Pass & Current Fault

The instrument is set to the dc 1100V range with the amplitude set to 220V, 600V, and 1100V. HV MUX3 from the HV DC OUTPUT SERIES PASS & CURRENT LIMIT circuit on the High Voltage/High Current assembly is measured for -0.035V ±0.02V. HV MUX3 is routed to Diagnostic circuit on the High Voltage Control assembly where it is connected to the SDL line for measurement by the adc circuit on the DAC assembly.

3111 A15: HV +DC High Voltage Output Fault

The instrument is set to the dc 1100V range with the amplitude set to 220V, 600V, and 1100V. This output voltage is divided to create MUX5 which is connected to the SDL line for measurement by the adc circuit on the DAC assembly. This failure occurs if the expected output voltage is not within 12% of the nominal.

3112 A15: HV +DC Ref/error Amplitude Fault

The instrument is set to the dc 1100V range with the amplitude set to 220V, 600V, and 1100V. The control signal AMPLITUDE from the Magnitude Control circuitry of the High Voltage Control assembly is measured. The nominal gain from AMPLITUDE to HV OUT is 135. This gain is checked by measuring AMPLITUDE to be 0.0074 of the nominal output ±25%. AMPLITUDE is divided to create MUX7 which is connected to the SDL line for measurement by the adc circuit on the DAC assembly.

3113 A15: HV -DC Preamplifier Fault

The instrument is set to the dc 1100V range with the amplitude set to -220V, -600V, and -1100V. The output of the DC HV AMPLIFIER/AC SENSE BUFFER circuit of the High Voltage/High Current assembly is measured for 2.3V ±0.2V. This voltage is divided to create HV MUX2 which is routed to Diagnostic circuit on the High Voltage Control assembly where it is connected to the SDL line for measurement by the adc circuit on the DAC assembly.

3114 A15: HV -DC Series Pass & Current Fault

The instrument is set to the dc 1100V range with the amplitude set to -220V, -600V, and -1100V. HV MUX3 from the HV DC OUTPUT SERIES PASS & CURRENT LIMIT circuit on the High Voltage/High Current assembly is measured for -0.035V ±0.02V. HV MUX3 is routed to Diagnostic circuit on the High Voltage Control assembly where it is connected to the SDL line for measurement by the adc circuit on the DAC assembly.

3115 A15: HV -DC High Voltage Output Fault

The instrument is set to the dc 1100V range with the amplitude set to -220V, -600V, and -1100V. This output voltage is divided to create MUX5 which is connected to the SDL

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