Hit a snag with my Space Invaders restore with a new problems that cropped up last weekend with my lights. The first is when I turned on my game and sections of of the chasing lights in the back box are out. If you start in a corner and divide the lights in groups of four, every other group of lights are out. Also, the right side of the creature lights are out as well. The light on the left side are on with a bit of flicker. I’ve put new solder on J1, J2 and J3 on the aux lamp board thinking that might fix it, but no luck there. The wired things is that these problems this the first time in the year I’ve had this game that this happened. All the boards are original except the MPU board, which is an Alltek. I've looked through the schematics and for the creature lights, each light grouping is tied to a different MC140288 IC.

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They are different. It's leg 4 for U2, leg 5 for U3, leg 4 for U4 and leg 5 for U5. For the door frame, I'm at a loss of how to read the schematic since there's lots of ways you can interpret left & bottom and right & top for the pin out in J2 and J3.

Verified that both the light board and light aux board are good by trying them in a friend's 8 Ball Deluxe... Also later today I got the game working after I noticed the Alltek MPU board was only attached by standoffs and I attached a screw to ground it to the backbox... and later the game stopped working again...so back to the drawing board...

Found the problem and fixed it. The high voltage/solenoid board had corrosion/lite surface rust on the bottom side of where the corner grounding screws go. Cleaned up both spots and the game works like a champ. It ever brought the sound board back to life!

I've got an issue that I'm hoping someone can help me out with. My Space Invaders will stop playing any sounds after after 30 minutes of play. If I turn it off for a while, the sound works again. I've previously replaced all the capacitors and reflowed all the solder on the connectors. Anyone have any suggestions to fix this issue?

I've noticed that U3 gets noticeably hotter than the other chips and I've replaced it with a NOS 6808 CPU, but that didn't make an improvement. Thanks on the suggestions guys, I'll try them out and report back.

Using the "upside down canned air" trick, U4 is the culprit. I'm going to pull the chip once I get some Deoxit and see if that fixes it. Else, I guess I'll be ordering a new rom from Action Pinball.