It's been a long time since I used one of those power supplies, probably more than a decade. I like the low noise (acoustically and electrically), but I've never understood why HP built versions without a programmable current limit (I should rather say: I wouldn't want to do without it). I've seen a video (actually, I think more than one) about these power supplies where capacitors leaked badly, destroying traces and causing leakage currents that affect operation. Although I can't remember whether these were HP or Agilent branded, I would certainly inspect/measure and potentially replace the caps if I wanted to keep these supplies. I was really surprised to see these problems, because I rarely had any bad caps in my old HP gear (6060B, 5334B, 33120A etc.). One notable exception is the 53131A (in my case Agilent) with its SMPS - and it's a type of equipment that is common to see many hours of operation.

If you're interested, I've got an extra HP 8920A RF Communications Test Set I would let go inexpensively. It has errors in the RF_Diags tests but does boot up and has all menus working.. Amtronix Instruments Calibrated and upgraded the one I have on my bench. They will also repair the 8920A. Chris S knows who I am if you want more info or to play with it before you buy. Everson Wa.