HP 8648 A/B/C/D - Changpuak.ch

5c-6 Service Error Messages
604
Description
Cause
What To Do
605
Description
Cause
What To Do
608
Description
Cause
What To Do
611
Description
Cause
What ‘Ib Do
612
Description
Cause
What To Do
+38 Vpower supply failure
The +38 V diagnostic test point decreased by more
than approximately 2.2 V.
The +38 V supply on the A2 power supply has
failed.
Check the +38 V supply.
ALC out-of-lockdivhetmainband
The ALC loop is out of lock in the indicated bands.
Either the A6 output has failed, or the signal from
A5 synthesizer has failed or the A4 reference has
failed. If only the het band has failed it is possible
that the A4 reference has failed.
Check the input to the A6 output from the A5
synthesizer and the A4 reference.
Synthout-of-lockdivhetmainband
The synthesis loop is out of lock in the indicated
bands.
Either the A5 synthesizer has failed, or the signal
from the A4 reference has failed.
Check the input to the A5 synthesizer from the A4
reference.
200kHzreferencemissingat synth
The A5 module indicates that the 200 kHz
reference signal from the A4 module is not being
detected.
Either the A4 module has failed to output the
200 kHz reference signal, or the A5 module is
failing to detect the signal.
Check the 200 kHz reference output of the A4
module at the input to the A5 module.
Reference out-of-lock at10 MHz
The A4 module indicates that the 10 MHz reference
VCO is out-of-lock.
Either the A4 module has failed or a bad external
reference is connected.
Disconnect any external reference and power-up
the instrument again or replace the A4 module if
the error is still present with no external reference.