Hi geekhack!
Some time ago I came across a Cherry G80-1501HAD in a very poor condition. It was pretty cheap, though, so I decided to give it a try. Thought it may have survived if it's a Cherry.
Unfortunately the board came in a shape way worse than expected. The obvious yellowing and some dust/dirt on surface is one thing, but the insides... wow, that was
unholy. I still didn't manage to get everything off.
Here's what I come with - the board doesn't work any way I connect it to my PC, whether it's through a DIN-PS/2 adapter, or DIN-PS/2 adapter attached to a USB-PS/2 adapter. Some LEDs do blink on the keyboard (the Num Lock usually stays on - I can't turn it off, so there's definitely something wrong) and it inputs random gibberish.
So here's my question - is it a compatibility problem (as in the keyboard's XT for some weird reason and it sends the wrong codes), a hardware problem (I mean it's still pretty dusty) or a combination or both? Could rinsing the keyboard in rubbing alcohol make it work again? I looked for some signs of damage, but didn't find any obvious ones at a first glance. It'd kinda feel bad to have to throw out this many vintage black MX's

Gory shots below, beware!
https://imgur.com/a/XkHJI29