MV-1A wierd graphics problem

I've just picked up a cheap MV-1A board sold as faulty.

The board powers up to the cross hatch screen fine. The video test screen with red green blue squares displays perfectly.

However, when I insert a game cart the colours on the graphics are all wrong, even the neo splash screen goes a brown / red instead of black.

I've tried cleaning the cart slot but it's still the same.

Anyone know what could be causing this? Bad capacitors maybe?

Thanks.

Not sure on that one. I've never seen those symptoms so I can't comment.

The battery hasn't started to leak at all has it?

I had slightly similar issues before on a faulty 2 slot I picked up and when I took the cover off realized that some of the lines were corroded from the battery just starting to leak out.

I've checked the battery. There's some minor residue on the surface of the battery itself but I can't see any corroded traces.

I might whip the battery off anyway to prevent future problems...

doctor_shred said:

I've checked the battery. There's some minor residue on the surface of the battery itself but I can't see any corroded traces.

I might whip the battery off anyway to prevent future problems...

Click to expand...

Definitely do that.

And RJ is the guy to ask about this, but you can also just check all those traces with a multimeter nearby to make sure there aren't any lines that have been damaged by the battery. Probably not a bad thing to try especially since you'll be swapping the battery anyway.

I've cleaned up the battery and surrounding area. It was mainly dust - I'll remove the battery to be on the safe side but there are no damaged traces on that part of the board.

On close inspection there are a few tiny scratches on the solder side of the board with exposed but not broken copper traces. These seem to go to the Yamaha chip (sound chip). This couldn't be the cause of the wierd colour problem could it?

I don't have a multimeter to test further at this stage.

doctor_shred said:

I don't have a multimeter to test further at this stage.

Click to expand...

You need to get one if doing any electronic repair.