Technical data

Service 2
Troubleshooting Hints
E3632A Service Guide 55
Unit reports errors 740 to 750
These errors may be produced if you accidentally turn off
power the unit during a calibration or while changing a
non- volatile state of the instrument. Recalibration or
resetting the state should clear the error. If the error
persists, a hardware failure may have occurred.
Unit fails self-test
Verify that the correct power- line voltage setting is selected.
Also, ensure that all terminal connections are removed while
the self- test is performed. Failure of the DAC U21
[1]
on the
top board will cause many self- test failures.
Bias supplies problems
Check that the input to the voltage regulators of the bias
supplies is at least 1 V greater than their output.
Circuit failures can cause heavy loads of the bias supplies
which may pull down the regulator output voltages.
Check the voltages of bias supplies as tabulated below.
[1] For serial MY53xx6xxx, failure of the DAC U36 on the top board will cause many
self-test failures.
Table 2 - 1 Bias supplies voltages
Bias supply Minimum Maximum Check at
+5 V Floating +4.75 V +5.25 V U11 pin 2
–5.1 V Floating –4.75 V –5.25 V Anode of CR5
+15 V Floating +14.25 V +15.75 V Anode of CR9
–15 V Floating –14.25 V –15.75 V Cathode of CR10