Neo Geo, Backup RAM Error, dip switch 1 for service mode?

telmnstr

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Neo Geo, Backup RAM Error, dip switch 1 for service mode?

Hello everyone,

I just got my first neo geo and it's a bit of a project.

I tried registering on a forum dedicated to Neo Geo stuff, but while my account is activated I can't seem to post.

It's a 4 slot and throws an error on power on about the backup RAM being bad. WRITE AAAA READ AAAE. Checked the OE, CE and WE pins from the SRAMs on the board and the traces are good to other chips. Not sure if the one 32 DIP chip is good or bad.

The battery had not leaked, but I removed it anyways.

I read that changing the 1st dip switch to ON should throw the machine into a service menu where I should be able to access a page to blank the backup RAM. I tried both 1 on and all 8 switches on, but it still just comes up with that same backup ram error. Is this normal? I can't find a reference if the dip switch will force service menu when there is an error present.

TIA for any insight!
 
You can't get to anything with that error message. It has to be fixed first.

The Backup RAMs are surface mount chips. It's the 2nd SMT chip from the front of the board that you need to replace. If you can't do surface mount chips then PM me as I do a LOT of repairs on those boards. (Check my repair logs. ;) )

Right now I'm holding folks off until after the first of the month as I have to do a bit of travel for work.
 
Not trying to do CM out of any business here, but if you don't have a rework station you might want to look into a product called Chipquik.
 
Ah okay. I shouldn't have much trouble doing the smd sram. I looked at the chipquik last night, looks pretty wild. Was trying to figure out what the alloy is :)

Going to order the sram here in a second. Kind of odd they fail so much.
 
I sell them on my site if you have trouble finding them. It's listed as a 62256 SMT SRAM chip.
 
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