Neo Geo with Backup Ram Error B240 Fixed

NW_Hooligan

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The internet tells me that the battery leaking is often the cause of these errors. This one took me a while to track down. I peeled back most of the foam backing, removed the battery, and cleaned up the backup portion of the PCB. I did not see anything obvious. Next, I checked continuity between all of the chips, and I couldn't find any broken traces. Must have spent an hour testing each one. I was getting ready to just desolder the RAM and put in a new one, but after some more searching, found that the B240 may be an error which is not caused by the chip itself malfunctioning.

Finally I pulled up and cleaned off all of the remaining foam backing, and it jumped right out at me. A corroded via, just to the left of PC5. I tried to clean out the via and see if I could get some solder back in there to make a connection, but it just was not working. In the end, I just soldered a jumper from Transistor Q1 to the 20th pin of one of the backup RAMs. Please excuse me for using wire of too thick a gauge and for having lousy soldering skills, I am just getting into doing arcade repairs after having only really fiddled around with NES and PSX consoles in the past.
 

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Nice work around, hey we all gotta start somewhere. Glad you have her up and running again!
 
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