Power Supply - HP 400E Operating And Service Manual

Model 400E/EL Section V
Paragraphs 5-36 to 5-41
NOTE
The test voltages shown in this section are
nominal. A tolerance of +5% is allowable.
Table 5-5. Troubleshooting Guide
SYMPTOM PROBABLE TROUBLE
No response to input. Fuse A2F1 open.
Instrument will not uprange above Relay K1 stuck closed.
1 volt, but works on 1 volt range
and below.
Instrument will not downrange be- Relay K2 stuck closed.
low 3 v, but works on 3 v range
and above.
TP5 voltage cannot be properly Ac output circuit (A2Q15, 16).
adjusted.
TP4 voltage cannot be properly Meter amplifier (A2Q8 - 13).
adjusted.
5-40. POWER SUPPLY.
5-41. Check with a de voltmeter (410C) at TP1 and TP2 for +26 volts and -26
volts respectively.
If the TP voltages are improper,
check the voltages listed
5-11