centipede pcb wacky colors

RedlandMan

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this pcb was in my cab before. It worked fine till one day i moved the cabinet forward to check something and when i put it back most colors were gone. When i turn it on ill get one of the 2 pics below and if i turn it off/on ill get the other pic. Self test checked out ok but if i try and check the colors no change, same color all the time.Ive put another set of roms just in case but no change. Im going to start trouble shooting it tommorow but if anyone has had this problem at least you can point me in the right direction. Thanks ,Luis
 

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Replace the two 24-pin sockets at the color ROMs. Then double-check the +5V at pin 24 on both.
 
Replace the two 24-pin sockets at the color ROMs. Then double-check the +5V at pin 24 on both.

Board has dual wipe sockets and i checked the roms sockets for continualy from chip legs to back of board and all checked out ok. Should i change sockets anyway?
 
oh come on, atari sockets are greeeeat!

just changed out some on a atari atarians board :p
 
Board has dual wipe sockets and i checked the roms sockets for continualy from chip legs to back of board and all checked out ok. Should i change sockets anyway?

Fairly sure it's a problem around the character ROMs. If they have dual-wipe sockets then likely the board has been worked on previously. Check continuity between each pin and its corresponding trace on the board. Is the +5V @ pin 24 ok? Can you swap in known/good ROMs from another board?
 
Fairly sure it's a problem around the character ROMs. If they have dual-wipe sockets then likely the board has been worked on previously. Check continuity between each pin and its corresponding trace on the board. Is the +5V @ pin 24 ok? Can you swap in known/good ROMs from another board?

Here is a pic of the sockets. I put a known set of working roms on this board as well as put these roms in a working board and no change. 5V is good and all roms. Ill start checking all pins on roms. What puzzles me the most is why i get so many changes every time i power on/off.
 

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Also worth checking the Color RAM circuit and working backwards from there - for example, the 82S25 RAM at L7 could be faulty.
 
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