[Test-Equipment] Tek TM503?

[Eugene Hertz]

Hello there. Anyone in test-equipment land ever try to fix one of these (tektronics TM503 is a power supply mainframe to hold plug ins)? Power supply was a mess, the DC outs were more than noisy... they looked more like AC outs! 

While trying to troubleshoot, I blew the fuse and saw that the fuse was somehow permanently attached to the fuseholder, rendering the fuse holder unusable. So, I began the task of trying to dismantle the rear power supply section to get at the fuse holder. Seems there is one black grounding wire that connects from some pin on one of the card connectors to the chassis. It is very short and prevents me from pulling the ckt board out too far. Short of cutting this wire, I cant figure out how to get in to take it off its little binding post. 

For the life of me, I cant get that stuff dismantled! Any observations/help would be much appreciated.  

Also, I think the real problem is with the 33.5vdc section.  Can anyone educate me what a scope trace would look like when connected to the DC out if the rectifier was bad or if the capacitor was bad? How does one figure out which of those components is bad? (as you may have guessed, I am brand spankin' new to fixing equipment)

thanks
Eugene