HP 8566B spectrum analyzer – repairs in progress

[Today’s run: 12 miles]

I recently received delivery of the HP 8566B which I purchased as surplus from Uncle Sam.

Plugging the thing in gave me less than satisfactory results, but it was advertised as having a bad display so I figured it might.

After chasing down a good manual for this particular rev of the thing, I was thinking that maybe I had some mismatched power supply boards, some old and some new.  But I got a bit closer and traced two circuit board lines back to where they went under an electrolytic capacitor.  Things looked ok from the bottom of the board.  I figured I would need to take that cap out so I could see what happened underneath.  Here’s what happened underneath!

It looks like this cap has been leaking acid stuff for a long time.  It ate away the traces which were supposed to be meeting at the + hole.  (removed reference to gold traces… probably just copper.)

Here’s the bad boy.