MV-2 with corroded traces "Backup Ram Error"

Hello everyone.

This is just a friendly reminder to replace the batteries in your boards.

Also, was looking for some other opinions. I got this board for free from a friend of mine. Obviously the battery leaked all over the backup ram area.

I've patched a number of traces, and replaced the two RAMs, and the 74x32. Ignore the ugly one in there, I've since gotten a new one from mouser.

So it started with a Backup Ram Error 5555/D755 and I worked from there. At one point I was getting the dreaded B240 error. I replaced the resistor (that was open) by the 1815 transistor and got that cleared up.

So, now I'm stuck with this,

BACKUP RAM ERROR
Address: 00D00000
Write: 5555 READ: 0055

I'm guessing it's the enable pin on one of the two RAMs? I'll have to double check all the traces.

My question here, does anyone have pinouts of the cart slots on a MV-2?

I've attached pics for your viewing/horror. This is probably one of the worst I've ever seen, but I'm determined to make it work. ANY help at all is appreciated. I'm reaching my whits end with this board

My first thought is that since you soldered to those corroded areas, it's still not making good contact. Have you verified with a multimeter by touching the top (non corroded) part of the legs on the ZMC2?

Also, see the saged advice from MKL about the error you're receiving. It helped me fix a very similar backup RAM error on a MV-2 as well: http://www.neo-geo.com/forums/showthread.php?118684-Backup-RAM-errors

Use a fiberglass pen to rub the corrosion off the legs.

Xian Xi said:

Use a fiberglass pen to rub the corrosion off the legs.

Click to expand...

I second this. If you do not have one, a pencil eraser might work well, too.