Check all the tilt switches. There are 4. One on coin door, one under playfield, the tilt pendulum and the rolling ball switch (inside coin door to the left. When it made the tilt noise did the tilt light in the back glass light up? (lower center in butt crack).

Ballys of this era: Connectors, Connectors Connectors. Start by measuring power supply voltages, then move across the other boards and check that each voltage is still good after going thru connectors. If the big connector on the upper right of the solenoid driver/voltage regulator board (large board, upper right) is original, it needs to be changed.

If by wiggling connectors/wire harnesses you get the game to start, then you have done some diagnosis, but the only repair is replacing connectors. Do both sides: headers (pins on board) and connectors (ends of the wire harness).

Good luck,

Don C.

Yep, if you added a new MPU but did not re-pin all the connectors, you most likely will see flaky behavior.

Check your voltage at the alltek, even if the little light says it's fine.

Almost all games of this vintage need all connectors repinned. Solves lots of headaches.

Check the fuse located under the playfield. It could be blown, which would explain why the coils aren't firing (except for the knocker, which is on a different circuit)

I'd definitely start with connectors as far as the sound issue, both on the sound board and mpu board. As was said earlier, if reseating the connectors fixes the problem, don't wait--replace the connector pins. And even if replacing/re-flowing the connectors doesn't fix the issues, at very least you can rule them out and proceed from there. I'm really surprised how often the problems on these games comes down to connectors.

For that matter, i think it's also worthwhile to take a closer look at the rectifier board. Any burned up connectors there? I always replace the male header pins and female connectors on the rectifier board when i get a game of this vintage. Voltage problems (often resulting from old, worn-out connectors) starting at the rectifier board can lead you down all kinds of diagnostic dead-ends elsewhere. So make certain all connectors are good there, and that the fuses are properly rated and the fuse clips are good and tight.

One last thing: the big capacitor on the power supply board--does it look original? Many had a big metallic blue one. If so, you'll definitely need to replace it to ensure good 5v and 12v supplies.

Good luck! Xenon is a great game, can be very difficult!

You may just want to first reflow the connectors to see if that is the issue. Once you validate, then look to replace.

Good advice. Since i have a good desoldering gun, i always just replace them. But re-flowing is often sufficient (unless any pins are really burnt)...and is less likely to create problems in the process (lifting solder pads/traces, etc). So yeah, OP should probably just re-flow first (and replace female connectors where necessary)...