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Author Topic: Super Pacman RAM error  (Read 1909 times)
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deadite
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« on: March 26, 2014, 01:06:53 pm »

 I have a Super Pacman that is showing RAM errors. I have checked the voltages, and they are 5.04 Volts on the RAM chips. At first I was getting a RAM 7 error, so I replaced the 2114 RAM at the 2D location. Then I was getting a RAM 5 error, so I replaced the 2148 RAM at the 3K location. Now I am getting a RAM 7 error most of the time and a RAM 5 error some of the time. I also found that one of the ROM chips was corrupted. So I erased it and reprogrammed it. That did not help with the RAM error. I am now at a loss, does anyone have a suggestion of what I could try next? Thank you in advance.
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STEVESPEEZE
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« Reply #1 on: March 26, 2014, 03:25:18 pm »

I have a Super Pacman that is showing RAM errors. I have checked the voltages, and they are 5.04 Volts on the RAM chips. At first I was getting a RAM 7 error, so I replaced the 2114 RAM at the 2D location. Then I was getting a RAM 5 error, so I replaced the 2148 RAM at the 3K location. Now I am getting a RAM 7 error most of the time and a RAM 5 error some of the time. I also found that one of the ROM chips was corrupted. So I erased it and reprogrammed it. That did not help with the RAM error. I am now at a loss, does anyone have a suggestion of what I could try next? Thank you in advance.


Examine the board traces and sockets
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iankellogg
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« Reply #2 on: March 26, 2014, 04:00:04 pm »

I have a Super Pacman that is showing RAM errors. I have checked the voltages, and they are 5.04 Volts on the RAM chips. At first I was getting a RAM 7 error, so I replaced the 2114 RAM at the 2D location. Then I was getting a RAM 5 error, so I replaced the 2148 RAM at the 3K location. Now I am getting a RAM 7 error most of the time and a RAM 5 error some of the time. I also found that one of the ROM chips was corrupted. So I erased it and reprogrammed it. That did not help with the RAM error. I am now at a loss, does anyone have a suggestion of what I could try next? Thank you in advance.

check the addressing lines. Sounds like a latch is bad. I dont know this board well enough to tell you exactly what to check but look at the schematic and check traces and chips in the address path.
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deadite
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« Reply #3 on: March 31, 2014, 04:38:54 pm »

Thank you for the reply. I did find one bad trace, so I jumped it. Still getting an error. I will continue to look for more.
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iankellogg
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« Reply #4 on: March 31, 2014, 04:41:02 pm »

Double check traces and most likely replace the SRAM chip. They go bad often.
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