Finally got around to testing a circa 1997 low-profile Dell Optiplex GXi I rescued a long while back, and it's refusing to boot. Beep code is a consistent 4-3-2. I know Dell uses their own set of beep codes as my main 98 rig is a heavily upgraded Dimension XPS, so looking up this model's service manual (which is thankfully available online), there's no listing in the beep code table for 4-3-2. Jumps from 4-3-1 (Memory failure above address 0FFFFh) to 4-3-3 (Timer-chip counter 2 failure). Absolutely no mention anywhere for 4-3-2.

I've tried:
Reconfiguring the memory with a multitude of known working modules
Installing and removing a COASt module
Unplugged every drive to where only the motherboard was getting power
Tried a different CPU
Different DOS and Windows boot disks
and every conceivable combination of the above. Still, nothing but 4-3-2 beeps.

I should note, there isn't any sign of physical or electrical damage in this system. Aside from the expected dust and a little bit of oxidation on the chassis, the inside is mint. All the caps appear fine (97 is well before the plague, and I have several other Dells of the same vintage with not a single issue between them). The disk drives appear to work, and there's no expansion cards installed. No HDD, as I was planning on using a CF to IDE adapter, but it's currently not installed. Not even Google is helping me on this one.

Anyone have any clue what's wrong?