Sorry I didn't see this before.
I have a HP 8160A, which seems to have the same CPU board. Also have the service manual. Here's photos of that part intact, the schematic, and the parts list entry for it.
Unfortunately the manufacturer code 28480 means HP themselves. But at least the part's values are given.
And thanks for reminding me this thing has a NiCad battery in it. Mine has been sitting on the shelf for a long time, with the battery completely dead. Would have started leaking soon no doubt. Removed now.
Someday I'd like to make something constructed entirely of nickel cadmium batteries, tantalum capacitors and bad electrolytic caps, and give it to my worst enemy.
Edit to add: And those stinky 'mains rated' polyester caps, that make the most vile stench when they (always) eventually fail. That I'm now sitting in a room with that smell.
I'd taken my 8160A apart to take that pic. Desoldered the old battery. Noticed there's one EPROM, desoldered and read that, socketed it (not going to bother with the other 3 mask ROMs, unless I find there is no online copy of the images. )
Put it back together without the covers and powered it up, thinking I'd have another quick look for the fault. (I didn't have a manual originally.)
Ah, but I should have taken the power supply apart first to check for those stupid caps. Took about 3 seconds to fail, with a big cloud of vile smoke. Now I have a large fan blowing air through the workshop, in one door and out the other, to try and clear it. An hour later and it still stinks. Also it's a cold evening.
There are two more of those caps in mains voltage parts of this supply. Hard to get at... so there goes this evening.
Edit: And 4 more on another board, also with mains voltage across them. So 7 in total.