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Align Issue with E4402B

Question asked by tflex_mike on Jan 10, 2013
Latest reply on Jan 16, 2013 by tflex_mike

We have an E4402B with the following options: 1DR, 1DS, 1D6, B72, 1D5, A4H, AYX, AYQ, 1DN

History: A co-worker used the output of the tracking generator as in input to a small low power amplifier circuit as we did not high a high frequency generator. I'm not sure what happened, but he phoned me to let me know the tracking generator was no longer working. He was only using the TG output and was not using the input to the SA. 

We bought a service manual and I have just started going through it. Turning on the SA, the screen showed the following:

+System, Alignments, Align Now, Align All+

Performing an +Align All+  doesn't remove the message from the display nor do any error messages show up in the Error History. 

I tried to align manually and running a +Align Now->RF+ but it gives the error message:

+RF Required+ and +Connect Amptd Ref Output to Input+ even though I have a cable connected. 

I can measure the 50MHz reference signal with another SA so I know that is working. 

What isn't working is the alignment signal.  Throughout the whole alignment process and following +Checking the 21.4MHz Alignment Signal+ in the service manual, I never see any 21.4MHz signal from cable W2/ input to the A3 IF assembly (A3J2).

The other SA only measures up to 1.8G so I cannot verify the 1st IF output, but measuring the 2nd IF output, it doesn't show anything at 321.4MHz. 

So, is the A8 RF assembly pooched? It would make sense since the TG isn't working either. 

Any suggestions on further tests to run before forking out the cash for a new RF assembly?