开云体育

Hello,

I am considering the purchase of an HP 35665A Dynamic Signal Analyzer for my home lab. I have located a bargain priced unit; however, the unit displays the following in a message box. "Calibration Failure (Change state of AUTO CAL to remove this message.)" Page 1 of the test log seems to show all items passing; however, page 2 indicates the unit Fails "Quick Confidence". The instrument appears to be in fairly good condition cosmetically. The CRT appears to be in good shape and the menus can be navigated with the front panel controls.

I have little experience with this instrument, but have used HP 3562A and HP 3563A instruments years ago. Of course these units were owned by my employer and were well maintained by our internal Calibration and Repair Lab. My desire for the unit is to help with developing some hobby projects that I am working on with my son. He is studying electrical engineering, at Georgia Tech, and I am trying to give him hands-on experience with some interesting equipment.

I am an experienced electrical engineer with a lot of background in controls, and analog design, and am not afraid to tear into just about anything to attempt repair. However, I know some of these older HP instruments include custom Hybrids, and other components, that might be hard to find.

Does anyone know if there is a common, or most likely, failure that generates this message, or is it a "catch-all" type condition that could take a lot of effort to resolve? I have not been able to locate a full complement of manuals for this instrument, so my hope is that perhaps the "Auto Cal" may simply require an external cable be in-place from the source to the inputs, or some other simple explanation.

The seller is only asking a few hundred dollars, but for about $400 to $500 more I can get a 100% working unit that has been calibrated. I am just looking for some guidance as to the effort I might be facing to resolve the Auto Calibration failure. Your input could help me decide to take a risk, or to instead lay out the extra funds to avoid ending up with a boat anchor. I enjoy the challenge of repairing old equipment, but at this time I already have enough items in need of repair :-)

Thanks in advance for any guidance.

Kind Regards,

Joe

Joe Egan
joe.egan@...

A dead battery in the RAM backup is the first place I'd look.

FWIWE,
-John

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