HP 8647A - Page 125

613
Description
Cause
What To Do
6 14
Description
Cause
What To
Do
615
Description
Cause
What
To Do
616
Description
Cause
What to
Do
617
Description
Cause
What To
Do
Reference out-of-lockat 1GHz
The A4 module indicates that the 1 GHz reference is
Either the
A4 module has failed or a bad external
reference is connected.
Replace the
A4 module.
out-of-lock.
400 Hzmodulationsourcefailed
The A3 board indicates that the 400 Hz modulation
source is not present.
Either the
200 kHz reference signal from the A4
module has failed, or the A3 has failed.
Check the
200 kHz reference output of the A4
module at the input to the A3 board.
1kHzmodulation source failed
The A3 board indicates that the 1 kHz modulation
source is not present.
Either the
200 kHz reference signal from the A4
modulation source has failed, or the A3 board has
failed. However, if the 400 Hz modulation source has
already been tested, the failure is most likely the
A3
board.
Replace the
A3 board.
AMmodulationpathfailure
The AM path detector indicates a failure at the
output of the
A3 board.
Either the signal output has failed, or the detector
has failed.
Replace the
A3 board
FM modulation path failure
The FM path detector indicates a failure at the output
of the
A3 board.
Either the signal output has failed, or the detector
has failed.
Replace the
A3 board.
5c-6 Service Error Messages