Bad work ram on a GUNBIRD pcb

Hi,


This week I received a GUNBIRD pcb but unfortunately it's is a bootleg pcb that is showing bad work ram (WORK RAM=NG) after the rom test.


Here's a picture of the pcb:




I need help to identify what chip is used for work ram, i took more pictures to help:














Any tips about what chip is used for work ram?

The 62256-25's are RAM chips. If you don't have a logic probe then shotgun them all.

Those SRAM chips next to the EPROMs are probably the Work RAM.

The easiest way to find which RAM chips are which is to identify which ROM chips are which. The MAME entries in the MAWS database shows which ROMs are graphics (signified by gfx) and which are sound and program.

Too bad it's down right now. If you try a Google search for the MAME info on the board you can try to view the Google cached data for it. I did that 2 days ago for a Strikers 1945 board I was repairing.

If you have an old 486 board laying around, many of them have old Cache RAM that can be yanked and used to replace that 62256-25 SRAM on that game board.

RJ

Another method would be to hold down one of the address/data lines on each of the suspect ram and see what error message appears at boot up, if the message changes (to include some other "ram-ng") you can eliminate that device.