MV4 slot graphical issues

Hey all, been lurking these forums for a bit as I’ve been doing a quick restore on a big red I picked up in a trade, which has been my first Neo project...I’m finally getting it all back together(was worried about getting the body work done before winter so i had not started looking at the board until after I got it inside)

It came with three carts, Samurai Showdown II, World Heroes and Bust a Move. I tested all three in a one slot I picked up and all work fine. All three games present with issues on the 4 slot, and some(shodown) will not boot at all in certain slots giving the crosshatch, but will start up in others, while Heroes works in all slots with slight graphical issues. The “Winners don’t use drugs” screen always comes through perfectly though. Attached is an image of the various glitched graphics I’m getting through the board.

I’m pretty new to board level work so I’m not even sure where to start troubleshooting this, so any steps in the right direction would be much appreciated!

https://www.dropbox.com/s/emieb3gkn49pt4i/Photo Oct 05, 9 35 03 AM.jpg?dl=0

The first thing you should do is remove the old NiCd battery if it's present. They are notorius for leaking and destroying traces in that area. Inspect that area for bad traces and the top board.I'm sure you'll find something. You will also want to burn or obtain a copy of the
[url="http://smkdan.eludevisibility.org/neo/diag/]DIAGNOSTIC BIOS[/url] which is great for pointing you in the right direction when troubleshooting.
I'm assuming you own a multi-meter and logic probe which are must haves.
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The battery had already been replaced before I received it thankfully. There are two traces on the inside near where the battery was that look kind of skunky but test well.

I'm getting something similar on my 2-slot (I had assumed it just needed a heavy cleaning after sitting for so long, but apparently it might be more).



Any ideas?

So this ended up being simply because all of the cartridge slot contacts were REALLY dirty. I spent about 15 minutes with each one the first time...another 20 with each solved the problem.

tweak said:

So this ended up being simply because all of the cartridge slot contacts were REALLY dirty. I spent about 15 minutes with each one the first time...another 20 with each solved the problem.

Click to expand...

What did you do for the cleaning process?