AnsweredAssumed Answered

Please recommend HP/Agilent 8720C repair company

Question asked by shaolin on Mar 21, 2009
Latest reply on Apr 18, 2009 by met
Hello, all,

I want to find a company/expert to repair our 8720C network analyzer. We appreciate it if somebody can recommend one.

The below is what happened to our 8720C network analyzer;

1) it works well before using HP-IB interface control;
2) 5 days ago, modified HP-IB control code to tune the power level
(HP-IB command: POWE) and power range (HP-IB command: PRAN). It still
works for a while.
3) Oh, My god, yesterday, we found that the power supply to the
amplifier (the amplifier is connected to the network analyzer) is
disconnected. we reconnected it back and run the HP-IB code again, but
the response measurement result from the network analyzer is always
the same, not matter how experiment configuration change. I shut down
the network analyzer and wait for a few minutes, then I want to turn
it on.  But it appears dead and I checked the fuse and it is broken. I
replace the fuse and found that there the green LEDs light of the
pre-regulator (A15) is off. I turned on the network analyzer. There are a few weird sounds at the first few seconds. And I found that the post-regulator (A8) green LEDs (8 in total) are all on. The fan is also on but not sure it is running normal. The display shows "Phase lock failure".