So my mildly-modded TAF worked perfectly fine (free play mode) prior to moving to my new house. Since the move, the start button does not start the game. I visually inspected all the soldered connections in the whole cabinet, and all appear fine. I ensured all the chips were properly seated. I ensured all the wire clips were properly seated. I replaced the start button with a new one. No change.

No here's where it gets weird: occasionally (maybe 1 in 20 power up cycles), I can get it to start by pressing the start button and slowly opening or closing the coin door... When it starts, it will play a full game perfectly. Sometimes, on the very next game, pressing the start button will immediately launch another game. Sometimes not. Also, I've found that if I can do the button/door trick, the trick usually continues to work until I power the machine down, and then it typically won't work on the next several power ups...

What am I missing? I'm having pinball withdrawal!

Updating this so anyone else with the same problem can see the fix. After much testing and trouble shooting, it seemed a very slightly loose ROM chip was the culprit. When the game started, everything worked perfectly, but it just wouldn't start reliably. Reseated the ROM chips and now it's started reliably over 500 times.