HP 54600A squished display problem, button problems and fix

I bought a Hewlett Packard 54600A oscilloscope a year or so ago.

Mine has screen burn in but was quite usable. It also had a problem with some of the buttons not working and the control pots being touchy.

This morning I turned it on after not using it for a few months (because of the issues it had).

I noted the display was squashed and the top of the image rolled.

I figured it was time to work on it.

I found that the buttons were filthy with a huge build up of black stuff under the 2 I needed the most.

I cleaned the switches and all the pots.

I researched the video image problem and found a forum where different people reported that either electrolytic caps C608 or C609 were the problem.

In my case since I had it opened I replaced both.

I also adjusted the B+ voltage to 14vdc as it was off by almost half a volt.

Problems solved.

 you might want to check for a rubber square on the inside of the case that has melted or turned to goo, mine had it and it was a sticky mess.