Good timing, as I'm currently in the (slow) process of refurbishing a Black Belt. This thing was disgustingly dirty and had a handful of problems when I got it. Slowly but surely making progress when I have the time, but I'll hit you guys up when I inevitably run into issues.
Btw, I HATE these bulb sockets. No apparent easy way to get to the bulbs (since the sockets' common wire is tight to the playfield and the solder would get broken off it I backed out the screws), so I've had to just bend each socket arm back (very tight access in some places). Then, the sockets themselves are ridiculously tight, hard to get the old bulbs out and new bulbs in. My fingers were practically blistered by the end of the night after replacing all the bulbs under the playfield.