I recently bought a dedicated 4-slot MVS cabinet with one game (Metal Slug). The board has some video issues.
When I power on the machine, the NeoGeo logo and the SNK Max 330 Mega tagline come up perfectly, but when Metal Slug starts, the graphics and sprites get all screwy. It looks like whole columns of the screen are flickering/missing and random artifacts are abound. It's pretty bad, but the color, sound and controls are fine. You can technically still play the game, it just looks WAY messed up.
Things I tried that didn't help one bit:
1) Put the Metal Slug MVS Cart in my friend's 1-slot cab. The Metal Slug Cart seems fine. You would think (hope) it was the Cart, but again, it works FINE on my friends 1-slot MVS.
2) Tried Metal Slug in each of the four ports on my board.
3) Cleaned the contacts of the Cart and the 4-slot board connectors really well with the appropriate contact cleaner (aerosol type with straw (non-lubricated)) and cotton swabs followed by long blasts of compressed air.
4) Took apart 4-slot motherboard and inspectd it for anything 'weird' looking. I noticed only one piece of solder that was touching another on the bottom board, but it looked like it was SUPPOSED to be there. Other than that, no visible black marks, circuit cuts, etc. I even held the board up to the light to see if any of the 'holes' on the motherboard that were supposed to be open were clogged. No dice.
5) Cleaned the motherboard surface and circuit paths really well with the Electronic cleaner paying special attention to the areans around the soldered chips.
6) Removed and re-seated the BIOS chip.
7) Ran hardware test on the board with the 'Test' button in the cab. It ran perfectly. All the menus are perfectly readable, so it's something that happens with the GAME kicks in. Like the graphics/sprite processor or something is screwy. Maybe memory?
After all of that, it is no better or worse than it was before! Anyone have a clue? I already ordered a replacment board, but I'd like to fix this one if possible!
-Rob
When I power on the machine, the NeoGeo logo and the SNK Max 330 Mega tagline come up perfectly, but when Metal Slug starts, the graphics and sprites get all screwy. It looks like whole columns of the screen are flickering/missing and random artifacts are abound. It's pretty bad, but the color, sound and controls are fine. You can technically still play the game, it just looks WAY messed up.
Things I tried that didn't help one bit:
1) Put the Metal Slug MVS Cart in my friend's 1-slot cab. The Metal Slug Cart seems fine. You would think (hope) it was the Cart, but again, it works FINE on my friends 1-slot MVS.
2) Tried Metal Slug in each of the four ports on my board.
3) Cleaned the contacts of the Cart and the 4-slot board connectors really well with the appropriate contact cleaner (aerosol type with straw (non-lubricated)) and cotton swabs followed by long blasts of compressed air.
4) Took apart 4-slot motherboard and inspectd it for anything 'weird' looking. I noticed only one piece of solder that was touching another on the bottom board, but it looked like it was SUPPOSED to be there. Other than that, no visible black marks, circuit cuts, etc. I even held the board up to the light to see if any of the 'holes' on the motherboard that were supposed to be open were clogged. No dice.
5) Cleaned the motherboard surface and circuit paths really well with the Electronic cleaner paying special attention to the areans around the soldered chips.
6) Removed and re-seated the BIOS chip.
7) Ran hardware test on the board with the 'Test' button in the cab. It ran perfectly. All the menus are perfectly readable, so it's something that happens with the GAME kicks in. Like the graphics/sprite processor or something is screwy. Maybe memory?
After all of that, it is no better or worse than it was before! Anyone have a clue? I already ordered a replacment board, but I'd like to fix this one if possible!
-Rob
I'll try to snag my friend's Samurai Shodown 4 tonite.
So, anyway, the cab went to a good home. <img src="graemlins/glee.gif" border="0" alt="[Glee]" /> 
The replacement came with a Euro BIOS which didn't differentiate between the two coin slots, but I swapped out the BIOS with the glitchy US board's BIOS and now everything is cool. I had never worked on an arcade machine before, and my girlfriend was a litle worried that it wasn't going to work once I put it back together. Misc parts had spilled into the kitchen! Works like a charm now though! 