Agilent Technologies 8648A Operation And Service Manual page 239

616
AM modulation path failure
Description The AM path detector indicates a failure at the output of the A3 board.
Cause Either the signal output has failed, or the detector has failed.
What To Do Replace the A3 board.
617
FM modulation path failure
Description The FM path detector indicates a failure at the output of the A3 board.
Cause Either the signal output has failed, or the detector has failed.
What To Do Replace the A3 board.
618
PM modulation path failure
Description The PM path detector indicates a failure at the output of the A3 board.
Cause Either the signal output has failed, or the detector has failed.
What To Do Replace the A3 board.
619
modulation 20 dB step failure
Description The 20 dB step attenuator has failed.
Cause The A3 board has failed.
What To Do Replace the A3 board.
620
Comm failure:
Description A serial communication failure has occurred with the indicated
assemblies.
Cause Either the A3 controller has failed or the indicated assembly has failed.
What To Do If one assembly has failed, check the indicated assembly. If multiple
failures have occurred, check the controller first. In either case, both the
controller and the assembly should be checked.
625
ROM checksum failure
Description The A3 controller has detected a mismatch in reading data from ROM.
Cause Either the controller has failed in reading from ROM, or the ROM data has
failed.
What To Do Check the hardware connection between the motherboard and the ROM
board.
Service Error Messages
5c-7