Bad video

[Franchise5]

I recently purchased The Simpsons Jamma.  I have it in my Sunset Riders cabinet and everything works except everything that has movement is distorted.  All the characters, enemies, etc... do appear correctly, but instead are scrambled.  Any idea of what would cause this, or how to fix?

[SirPeale]

Sounds like a ROM issue as opposed to a video one.  I'd have to see a picture to be sure.

Make sure the board is getting correct voltage.  Make sure the JAMMA harness is clean.  Reseat ROM chips (with it OFF of course).

[Franchise5]

I have other Jammas that work in the cabinet, so I believe the harness should be in working order, or is it possible it would only be a problem with this Jamma. 

Also, how do u reseat rom chips?

[SirPeale]

I have other Jammas that work in the cabinet, so I believe the harness should be in working order, or is it possible it would only be a problem with this Jamma. 

So rather than check the voltage, you're going to stand on the principle of "other things work here...this should too".

For all you know your supplying 5.5V to your boards, when you should only be supplying around 5.1.  Best way to blow a board is by giving it too much juice.

But what do I know...I just fix the things for a living.  You do what you want.

To reseat ROM chips, you want to take a jewelers screwdriver and lever the ends up on the chips *GENTLY*.  Then put them back down in the socket.

[CheffoJeffo]

I have other Jammas that work in the cabinet, so I believe the harness should be in working order, or is it possible it would only be a problem with this Jamma. 

Voltage differences caused by dirty harnesses or edge connectors will affect different games differently ... cleaning is usually my first step (followed immediately by checking voltage).

Best advice I ever received was "clean all the connectors and get a multimeter -- if you have cabinets, you need a multimeter."

Cheers