Hello Matthias - I had this problem on my 5370B - it turned out that the fan wasn't running, which resulted in overheating.
I hope this helps. Regards, John K1AE -----Original Message----- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Matthias Jelen Sent: Monday, June 08, 2015 9:28 AM To: time-nuts@febo.com; dk...@gmx.de Subject: [time-nuts] HP5370 Error 04 Hello! I´ve got a question to the 5370 experts on the list. I just received my new (old...) HP5370a. It performed fine for abt. one hour, then it started to display error 04 which means "PLL out of lock". A look in the service manual revealed that there are several reasons for this. I checked the VCO voltage on both interpolator cards, and indeed, one of them is out of the specified -6V..-3V, it runs to the rail (-12V). Even if the error is not there, the voltage is at abt. -7 V, so I guess it´s just on the edge. The other card is fine. Normally, I´d try the alignment procedure, but I´m missing the exotic HP pulse generator used for the alignment and I have no clue how I could easily substitute this one. Did anyone encounter this problem before? Is there a cure for this problem known to the experts? Any hints are highly appreciated... Thanks a lot, Matthias, DK4YJ _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
