FIXED! Pole Position RAM 27 error (RAM is good)

rmcelwee

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I have a Pole Postion video pcb that throws a RAM 27 error. I pulled the 9114 ram @ 7K, added a socket and replaced with a 2114 chip. The error is still there. I see pin #8 CE is pulsing and pin #10 R/W has activity. It looks like the LS7423 @ 6K and 7D are tied to this but they look the same as they do on my test board. I am a novice and looking for further ideas. Thanks!
 
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Where did you get the 2114? Is it tested and know to be working 100%? I made the mistake of buying some 'cheap' 2114s and they don't all work on the Pole Position pcbs I've been trying them on even after they test good on my NeoLoch
 
Where did you get the 2114? Is it tested and know to be working 100%? I made the mistake of buying some 'cheap' 2114s and they don't all work on the Pole Position pcbs I've been trying them on even after they test good on my NeoLoch

I think cheap 2114 from China. I did not test them on my NeoLoch because I assumed they were good. I clipped the original ram off the board and used another from a parts board so I would have to assume it is not a ram problem (two original and two new chips gave the same error). Of course, all 4 could be bad but I would not think so.

EDIT - I did find a board with some socketed 9114's (untested) and threw one of them in. Still have the RAM 27 error.

Thanks!
 
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Pole Position RAM 27 error (RAM is good)

The speed of 2114s matters. PP will often still throw a ram error with a slower 2114.
 
I found the problem. I was checking for continuity from the 9114 ram @ 7K to the other components. I found that pin #2 was supposed to connect to pin #8 on the custom @ 7E and it did not. I soldered a wire between them and the board is now working fine. Well the mountains aren't showing up very well in the background but at least the game mostly works now. I'll visit the mountain problem later. Thanks for all the help!

BTW, what size wire do you guys use for these patches? I didn't have anything small so I just used a wire out of an old CAT 5 lan cable.
 

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I found the problem. I was checking for continuity from the 9114 ram @ 7K to the other components. I found that pin #2 was supposed to connect to pin #8 on the custom @ 7E and it did not. I soldered a wire between them and the board is now working fine. Well the mountains aren't showing up very well in the background but at least the game mostly works now. I'll visit the mountain problem later. Thanks for all the help!

BTW, what size wire do you guys use for these patches? I didn't have anything small so I just used a wire out of an old CAT 5 lan cable.

Nice fix.

I use Kynar wire for patch work.
 
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