Ms. Pac-man PCB problems. I have invisible ghosts.

Eternaliquid

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My stationary characters are blocky and my moving characters are invisible. I can start a game and play, I just can't see ghosts or Ms. pac. I can still see the dots being eaten and am able too traverse the maze. All the sounds appear to be correct. Any ideas as to where I should start?
 

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The intro looks like pacman with ms pac character roms.

Yes, you would be correct about the Pacman intro. The game is not at my house and I only had a few minutes with it today. I forgot that I had pulled off the ribbon cable and popped a Z80 onto the board. So the blocky ghost could be from that, right? Either way, I still have game play with no characters visible. I can even eat the power pellets and eat ghosts.
 
Have you checked all the repair logs? Seems i've seen this before. Also, check Lawnmowerman.rotheblog.com
 
Have you checked all the repair logs? Seems i've seen this before. Also, check Lawnmowerman.rotheblog.com

I thought I had seen that as well, but couldn't find it. Just rechecked Lawnmowerman and found this -

Plays, No Characters in Maze or intro Screen. Dots visible & disappear as eaten.

(rare case) Dead 74LS157 at U5 of V-Ram Addresser (rare case).

You rock dude! Hopefully this is a fix.
 
So the (Dead 74LS157 at U5 of V-Ram Addresser) was a bust. I swapped out the 284 V Ram Addresser Daughter PCB with a known working one and had no change. Still looking for help on this one.
 
Have you checked the character ROMs and sockets? Probably worth replacing those ROM sockets and cleaning the legs of the EPROMs/PROMs there and/or verifying the ROMs with a EPROM programmer if you have one.

If that doesn't yield anything, I would probe the pins of the chips between the character ROMS and before and after the VRAM (5A, 5B, 5C, 4A, 1E, 2E, 3A, 3B, 3C, 3D, etc) and look for stuck pins.
 
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