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calibration failed, align_aif_main_gain

Question asked by tbayler on Apr 22, 2014
Hello everyone,

I have a question that I'm hoping someone can answer for me.  When I turn on my E4440A spectrum analyzer, it goes through all of the calibration and alignment and typically it finishes up and works just fine.  However, yesterday when I turned it on, it kept repeating the alignment process over and over again about every 5 minutes.  I also receive an error message that says *"calibration failed, align_aif_main_gain"* and another message that says *"system, alignments, align all, needed"*.  I did what the message said and aligned everything but it just keeps repeating itself over and over. I turned auto align OFF and took some measurements to see if it was even working properly and it seems to work fine until I get up into the 2-3GHz range.  When I input a signal of more than 3GHz my output level is around 5dB high.  Less than 3GHz I'm still a little higher, but closer to the number that I'm looking for.  I took some measurements here - Signal generator = -3.5dBm hooked to the power meter that reads -5.0dBm.  using the same -3.5dBm signal from the generator I hooked to the analyzer and got +1.48dBm @ 4GHz.  This confirmed my 5dB difference that I was seeing when measuring some of my 2nd harmonics.  Does anyone have any idea as to what my problem is? I'm guessing something is damaged with my analyzer because I tested using a different analyzer and did not see any problems.