They don't typically have cap failures but components in the low voltage circuit. I don't know if I have one that is already been fixed. If I had one to sell tested working it would go for $75 if you don't have a dead one for exchange. PM me if you are interested.
Yeah unfortunately when I picked this Tempest up today, the def board was the only missing component. I do have a few flybacks from older WG monitors and a board from a Ms. Pac WG monitor if you're interested.