Pac-Man Board of Unknown Origin

[Pac-Man Board of Unknown Origin]

Cebus Capucinis, wow, this is great information.  No offense taken at all. I appreciate the dumbed down version even if the engineer inside me doesn't like to admit it I have checked the power - actually, the first time I fired it up after cleaning the logic board I didn't have sound, but could play otherwise.  Found out that I wasn't getting 12VDC at all to the logic board (both 5V circuits were good).  Replaced a blown fuse on the power supply PCA and sound was restored.  Also, I've never been able to hear sound or play blind while it was glitching or scrambled so I kind of ruled out the monitor as the culprit, although that's likely not really exhaustive troubleshooting on my part.  I will try to check the capacitors as you suggested and inspect the board in detail this weekend.  I have cleaned the edge connectors as I've heard from reading other forums that those can cause trouble on these old arcade systems, not to mention my own personal experience with Magnavox Odyssey and Nintendo NES edge connector cartridges back in the 80's. I didn't take an eraser to them though, I'll try that.  Also, thanks for the advice on taking pictures and marking how things are oriented - it's a good reminder and I really can't hear that enough.  You mentioned mask ROMs, which I really don't know anything about but you pretty much described what they are despite the poor resolution on the picture.  They get programmed with UV or some photolithography magic or something.  Can exposure damage them?  Should their little windows be covered?  I'll post an update when I get it back together again and hopefully some pictures of it running.  Really appreciate the advice!

[Pac-Man Board of Unknown Origin]

Scotty, it is not Mazeman - although that game does look pretty sweet It's a clone of the Midway version of Pac Man in just about every way.

 

UPDATE: After a lot of playing around with it I was able to get the board to play.  I went through and removed all the IC's in sockets (is that what they are called?), cleaned them, and put it all back together.  It started up and played great for a couple days.  It was a fun couple days!  Then a glitch or two reared it's ugly head and game play gradually degraded to the point where it just shows garbage on the screen again during start up.  I am tempted to attempt to reflow the solder (with my soldering iron) on some of the IC's that are soldered directly on the board rather than in sockets.  I am wondering why cleaning the chips in the sockets brought is back to life, but then it gradually degraded again over time.  In my mind it seems like a bad solder joint could act like that, either on an IC or between a socket and the PCB.  I bought a couple of the IC's from Digikey to see if replacing one or two of them would help, but haven't worked up the courage to desolder and resolder an IC as it would really be taxing my soldering skills - not to mention I'd be shooting in the dark as to which IC is the culprit.  Thoughts?

[Pac-Man Board of Unknown Origin]

Okay guys,

 

I need some help with an old Pac-Man cocktail table.  First time poster here and noob with regard to arcade game repair.  I have an engineering degree, but alas, it's mechanical engineering (don't hate), and it doesn't help me much with PCA troubleshooting.

 

The History:

I have an old Pac-Man cocktail table that my parents picked up for $50 from a newspaper ad in the late '80s and I played a ton as a kid.  It had a few glitches in it then, and it's been sitting in my uncle's barn for 20 some odd years.  I needed a project and remembered this old thing and decided to dig it out and bring it to my garage.  It was full of mouse nests and wires were chewed beyond recognition. The control board and CRT were in surprisingly good condition (other than needing cleaning).  I gutted the harness and re-soldered and rebuilt the primary and secondary power harnesses and controller wires.  I plugged it in and got scrambled gibberish and grid patterns on the CRT - better than expected considering the state I found it in.  Started looking online for troubleshooting tips and found a lot about Midway Pac-Man tables and thought that must be what I had.  The table does not match any of the Midway table pictures and having gone through the table, it is clear mine was a retro-fit of some-sort.

 

The Problem:

The board does not match the pictures shown of the common Midway variety I've found online, although it has some uncanny resemblances.  No Midway logos on anything and there are some subtle differences in board layout and edge connector pin-outs from the schematics I've found online.  Chips appear to be Intel, Mitsubishi, and Texas Instruments along with a few I don't recognize - probably doesn't help knowing who made them.  I'd like to get this thing back up and running if possible, but can't find info on much else but the Midway versions - which maybe this is, just not an obvious one.  Or perhaps it's a clone or a predecessor/successor.

 

So what is this thing and is there any chance I can extrapolate Midway troubleshooting blogs here and other places around the web to breathe life into this thing again?  Looking for a clue or a starting point.  I can upload more pictures if needed.