HP 6033A series Service Manual page 55

A2Q3 (emit)
A2U5 (OUT)
A2R50, A2CR11 (anode)
A2R46, A2R47
To check if load on + 5V is shorted, remove jumper A2W3
+15V On A2 Control Board. Voltage regulator A2U12 regulates the voltage across resistor A2R29 to be 1.25Vdc. That
sets the current through zener diode A2VR1 at 7.5mAdc. The output voltage is 1.25Vdc plus 11.7Vdc across A2VR1 plus
the voltage across A2R34.
Circuit Included. +15Vdc bias supply circuitry from connector pin A2P1-27 through test point A2J3-2 on A2 control
board.
Setup. The Main Troubleshooting Setup, Page 48. Apply the ac mains voltage to the isolatlon transformer, and set the
external supply to 0Vdc.
Input:
NODE MEASUREMENT
≈ 24Vdc
A2U12(IN)
A2C17 (+)
Outputs:
NODE ( + )
A2U12 (OUT)
A2U12 (cath.)
A2VR1 (anode)
A2LR3 (cath.)
To check if load on +15V is shorted, remove jumper A2W1.
≈ 20V pk, 5µs pulses, 45KHz
2.5 Vdc
≈ 0 >V > 0.007Vdc
2.5 Vdc
SOURCE
A1U1, A1C1 (+)
NODE (-)
A2U12 (ADJ)
A2U12 (anode)
A2R34, A2R33
A2VR3 (anode)
MEASUREMENT
l.25Vdc
11.7Vdc
2.05Vdc
6.2Vdc
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