Hey all.
So after almost 6 months of banging away Al's garage band lives! Game starts and plays if you let the auto launcher timeout and launch. However if you press the button the coil does a sort of half powered fire, and the game restarts. Thought of maybe some gremlins in the diodes, maybe running voltage back to the tilt but switch test produced no laggy or weird strobes. Its odd because sometimes the game will do it in the middle of a game as well, once in mulit-ball. A soft sort of reset and start. Rebuilt the Power supply and reflowed and rebuilt several connectors as well. Anyone encounter anything like this before?

Mmm. I see what you mean. I'll try dialing up the +5 a half volt or so and see if it holds. What little I've banged out of it is really fun though. Hoping to update this weekend.

Would ya look at that! Game is up and running all the way through. Thanks for the help. Now all I need is a speaker panel and some new leaf switches for the bumpers. (someone replaced them with these odd ball EOS looking ones with no third leg for a diode. This bad boy has been a pill for sure. But the action is pretty good and I love the sub woofer and feedback on the flippers. Wish they had a color DMD for this bad boy.
Thanks for the help.

I will say this. Alvin G knew how to efficiently arrange a board, however the thin protective back left the power supply often getting damaged. Check your input connector, and the output connectors on P11 and P3. Also check the 5v fuse, as the cheaper china Bulb fuses have actually cause minor 5v fluctuations on my sys3 games before here at the bar. Let the game warm up and see if the issue improves, mine never changed. If yours improves it could be a simple dry solder situation. I reflowed every connector on every board of my game, and will probably be adding a 12v back box venting fan and probably pulling the 110v dmd and swapping to a modern 5. All in an effort to pull the high voltage lines from the circut and hopefully extend the life of the game. Though it will be in a commercial location running for up to 14 hours a day at a time.

Hey Guys,
So an update and hopefully some can chime in with their opinion. After a few days I swapped in a better looking dale/vishay dmd that had less outgassing than the previous one. Well after a few games the cut off issue cropped back up. I hooked my meter up and the 5v input for the mpu and while the 5v was running at 5.13 it was oscillating from 5.18 to 4.98. Hence the reasons for the cutoff from low 5v. Is the drop from the PPU board? Would rebuilding the 5v section solve this? Or is the DMD pulling voltage in a strange way? Certain animations are defanitly causing oscillation. Is some voltage drop/boost common for most pins? (within reason) or should 5v hold steady?

Just a post for others that encounter these issues on Alvin G. The thing that helped clear up my voltage oscillation issues that may help anyone else, is don't just replace and Reflow the solder on the back of the board. I ended up re-pinning most of the connectors on the board. Seems the actual line connectors hold up pretty well and are two sided, however burn and heat issues are rampant. I reflowed most of the 5v section after the bride rectifier and even jumped the 9v to the fuse holder section. Pay attention to the colors around the back area of the board and take care when pulling the pins as to not lift the pads. Just Ohm out the traces while the board is out as I've found the pad lift to be bad on these and I have a bench mounted vaccum pump. Still dealing with a bit of voltage drop on the 5v line, but its within a few hundreds of a volt so I think the game is fine with it. Alot of the playfield is well protected with fuses and solid relays, and the backbox is well laid out. Sad to see that heat wreaks so much havoc on these boards. I'm going to see how to maybe mount a 12v computer fan to move air across the heat sinks, that and I hope dropping to a low voltage DmD will really help pull the higher voltages off. Good luck out there.