I snared this little beastie from the 'bay; it arrived today. It was advertised as 'For parts or not working', with a note that it wouldn't power up and that the fuse was good. For the price, I figured it was worth a shot:
As noted, it doesn't power up - plug it in, press the power switch and from all external appearances, a whole lot of nothing happens. No lights, no cooling fan, no nothing. As advertised, the fuse checked out as good.
Externally, it looks almost brand new - the front panel is in beautiful condition, and other than a missing HP emblem on the carrying handle and a bent fan filter retaining screw it looks great. The missing emblem makes no difference to me, and the bent fan retainer was fixed in about 30 seconds with some gentle persuasion from a pair of lineman's pliers. This is as it came out of the box - no cleaning:
Removing the top cover (cake - 4 captive quarter-turn fasteners and off it came, with no loose hardware to lose) reveals the usual solid construction typical of HP instrumentation. There is beryllium copper fingerstock along the sides and top to bond the cover to the chassis, and the boards are further shielded with sheet metal covers:
This was a surprise - I was expecting a long electrostatically deflected CRT like what you find in a scope; instead it has a short little magnetically deflected one. It's so cute. I wonder, if you feed it, will it get bigger?:
There's similar bonding fingerstock for the bottom cover which is unsurprisingly retained by the same quarter-turn fasteners as the top, and the underside of the mainboard is basically a giant plane layer for shielding. It's protected by a sheet of Plexiglas, not readily evident at a glance in the photo:
Removing a metal cover exposed the power supply section:
Linear regulators on the main board. I suspect that the blue electrolytics on the removable card immediately above them are the filters:
The initial troubleshooting procedure I found in the manual on Keysight's site began with checking a pair of 12V bias supplies, which were operational and within spec.
The following step was to check the indicator LEDs on another board in the PS section. The lighted one shown indicates an overcurrent fault. (surprise, surprise!!)
That fault was then isolated to the main part of the instrument by pulling the board out of the edge connector to disconnect it from the array of linear regulators on the mainboard (it feeds them). When power was reapplied, the overload LED was off. This came as no great surprise.
Of course THAT troubleshooting sequence is in part II of the manual, which is not readily available online as a PDF that I've found, so further misadventures in troubleshooting will have to wait a bit until I get my hands on a hard copy of the two volume troubleshooting and repair manual. Off to evilBay...
-Pat