Ok so, this board was working when I last touched it. Now it's not. No beep, no video output, nothing, not even anything on the POST code card, just - - - -
Clock is there, activity on the bus, the CPU is not being halted. Activity seems to be a very tight loop.
Replacing the CPU, RAM, does nothing, so does messing with the jumpers. BIOS EPROM reads out fine, but I have yet to check the parity checksum. Replacing the keyboard connector also does nothing, BUT, if it's out, it starts up.
Cold start results in a short beep, with the message "8042 GATE A20 ERROR SYSTEM HALTED" (of course it's unhappy about a missing keyboard controller), with POST codes being (in reverse order):
43 42 41 40 3b 3a 39 38 37 36 35 2e 2d 2c 2a 29 28 26 25 24 22 21 20 15 14 13 12 11 10 0f 0e 0d 0b 09 07 06 03
A soft reboot results in black screen and 7 short beeps

Ok so scoping that out, VCC and Ground on the keyboard controller looked like a data pin. Someone suggested I have the sockets mixed up, and yes I did. The keyboard controller goes in the other 40 pin socket, the one furthest from the keyboard. Of course it does!

(I had this out before to test a different board with, seems like I didn't pay attention. And of course the sockets are not labeled)

I feel so dumb. Real bun moment. No brain, just fluff.

Sorry for the mess on the table

feeling kinda qt, might delete later idk

I bought a DS at a flea market and there's some cursed stuff on there

Gutted this PC monitor. I've been told a cat pushed it off a shelf and now the shadow mask is bend. Tube and case is going away, but I'm keeping the cool bits.