NAUGHTY MS PAC MAN needs logic probe

TheOldMaster

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My ms pac man has no ghosts or ms pac when the game is playing.

also get BAD W RAM 1

error message sometimes appears in test mode.

dots are being eaten as you move the control but ms pac and the ghosts are invisible.

really kind of cool to see but gets old quick....

Im leaning towards the v ram pcb?

Anyone have any tips to expedite my repair?

THANKS.
 
Thats not an uncommon problem and its usually either one of the 7489 rams or the ls283 below it. I would have to look at a pcb to give you exact locations.
The bad ram 1 is one of the 2114's. It usually wont boot with a bad 2114 but I have seen some that do on occasion. I would start by fixing that problem and go from there.
 
I'm getting bad w ram 1 on one of mine. I replaced both 2114's and I am still getting it. I am going to change the sockets unless someone know another cause for this error.

Jeff
 
I changed out the sockets and when it came up I saw

BBDD WQRBM 1

With several other characters on the the screen. Looks like it still says Bad W Ram 1 but with garbage over it. I reseated everything again. Change most of the roms and now I justget garbage on the screen. I've changed the processor too. Do I still have a ram problem or is it something else.

Jeff
 
I changed out the sockets and when it came up I saw

BBDD WQRBM 1

With several other characters on the the screen. Looks like it still says Bad W Ram 1 but with garbage over it. I reseated everything again. Change most of the roms and now I justget garbage on the screen. I've changed the processor too. Do I still have a ram problem or is it something else.

Jeff

Have you installed known good 2114's to rule those out?
 
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