Hey,
While looking for ready-to-use capkits for some of my machines I noticed several sellers advertised long life capacitors with 3000h garanteed.
I immediately thought 3000h wasn't much since a cabinet in operation BITD would reach that within less than a year and I don't think any operator...
I can see blue in your first picture, was it before it failed? Or is it present but faint?
Unfortunately a rejuvenator isn't a magic bullet if the gun is dead.
That sub board is original, to support bigger mask ROMs, just not the most common type.
I have it on my PCB too, I bought ~20 years ago, with all OG labels and keycus.
The reason for the missing labels on OP's board is the keycus is missing! Either it was bad, lost or the daughterboard was...
Not impressed? Shocking I'd say.
I'm under the impression that's a flaw they are well aware of, still they ask people to pay shipping both ways.
Sucks when you have to rely on a single entity with unprofessional attitude.