Agilent Technologies 6031A, 6032A, 6035A, 6030A - page 58

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+15V On A2 Control Board. Voltage regulator A2U11 regulates the voltage across resistor A2R99 to be 1.25Vdc. That
sets the current through zener diode A2VR3 at 7.5mAdc. T he output voltage is 1.25Vdc plus 11.7Vdc acr oss A2VR3 plus
the voltage across A2R100.
Circuit Included. +15Vdc bias supply circuitry from connector pin A2J 5-5 through test point A2J7-2 on A2 control boa rd.
Setup. The Main Troubleshooting Setup, Page 53. Apply the ac mains voltage to the isolation transformer, and set the
external supply to 0Vdc.
Input:
NODE (+) NODE (-) MEASUREM ENT SOURCE
A2C52 (+) A2C52 (-) ≈ + 25Vdc A1U4
Outputs:
NODE ( + ) NODE (-) MEASUREMENT
A2J7-2 A2U11-3 (ADJ) l.25Vdc
A2J7-2 A2VR3 (anode) 12.9Vdc
A2J7-2 A2VR3 (anode) 6.2Vdc
A2C50( + ) A2C50( - ) 13.8Vdc
To check if load on +15V is shorted, remove jumper A2W1.
-15 V On A2 Control Board. Voltage regulator A2U12 regulates the voltage across resistor A2R103 to be 1.25Vdc.
Circuit Included. -15 Vdc bias supply circuitry from connector pin A2J5 -6 through test point A2J7-21 on A2 control
board.
Setup. The Main Troubleshooting Setup, Page 53. Apply the ac mains voltage to the isolation transformer, and set the
external supply to 0Vdc.
Input:
NODE (+) NODE (-) MEASUREM ENT SOURCE
A2C55 (+) A2C55 (-) ≈ - 25Vdc A1U 4
Outputs:
NODE ( + ) NODE (-) MEASUREMENT
A2J7-21 A2U12-3 (ADJ) - l.25Vdc
A2J7-21 A2VR4 (cath) - 12.9Vdc
A2C54( + ) A2C54( - ) 13.8Vdc
To check if load on -15V is shorted, remove jumper A2W2.
Refer to Down Programmer, for the + 10.6Vdc bias supply, and refer to OVP Circuit, for the + 2.5V bias supply.