ms pac issues

death69inc

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this one seems to be fun
1st thing running on a test rig pac to jamma harness workgin on 2 other boards just fine

power up all 0's and fruit cycling from other trouble shooting pionts at vrams
replaced all 6 vrams to see if it cured the matter
0's went away now i have random garbage
pulled socketed reincerted all socketed chips nothing has changed
incert abc diag board gets worse garbage and cycling ..sounds in wierd loop with cycle
put orig aux boasrd back on sometime get little garbage and sometime get much garbage
replaced eproms now 0's back
replaced proms nothign changed
ran down traces for vram none are broken from scratches etc
checked voltages coming in +5 was only 4.8 so raised it now 12 is 12.5 dont think that will be an issue


here is what i see so far
two of many garbage screens with aux board installed bars dance other crap moves around
SSPX0964.jpg

SSPX0963.jpg


after abc diag board installed game rom
SSPX0965.jpg


after diagnoistic rom installed
SSPX0966.jpg

SSPX0968.jpg


from the picures you can see the diagnostic board is working i can do button tests etc just have no clue what im looking at lol

I have this thread on other sites but no responces
trying to save sendign out for repair

I already have one that needs to go out rather not have to many sent out
 
Might be worth replacing the sockets, and have you tried a different daughter board or Z80 on the current daughter board?
 
Might be worth replacing the sockets, and have you tried a different daughter board or Z80 on the current daughter board?


I have swapped the z80 in duaghter board
and used the abc board

so i dont think its the duaghter board unless its the socket on the board causeing it as both the abc and the aux board get wierd effects
 
Check the edge connector.It can cause all kinds of goofy issues.

i checked the edge connector it has some issues +5 tab on sodler side is ruff but I am getting full +5 threw it as tested after the edge conenction is made
 
Will it play as pacman with the daughter board remove and replaced with a z80?

Jeff

Technically, it'll be Pac-Man, but the 5E and 5F EPROMs will still have the Ms. Pac character information on them and the graphics will be a little screwed up... but gameplay wise, yeah, it'll be Pac-Man.
 
I know. I was curious if his daughter board was causing the problem. I had a similar issue with mine and it was the daughter board.

Jeff
 
i doubt it was the aux board as the sbc did the same thing

but i went ahead and tried fig wth either case no change inserting a cpu instead of the aux board
 
Good point. I missed that in your post. At least now you know the problem is somewhere on the main board.

Jeff
 
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