K7000 random Blue screen problem

Treydogg77

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Donor 2011, 2013
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K7000 random Blue screen problem I've got again. Every once in a while my background color use to go to a bright blue. I replaced the AC cord plug and it fixed the problem till today when I moved the cab to another room. Now the blue screen is back and the coin mechs are not registering coin ups. Any ideas what might might be causing this? Possibly a loose ground in the cab? Its a standard Jamma Dynamo cab.
 
First I tried another PCB "not cabinet mounted" and the screen came up green instead of blue. I had the control panel flipped down and jiggled the the control panel wiring harness which was flexing the jamma connector as well and the and the colors came back. Turned the game off and back on and the d*mn screen was blue. I tried jiggling the harness's again and got no color change what so ever just the blue background.
 
Check the pins on the jamma harness, over time they get pushed back to far and make little to no contact with pcb. Get a small jewelers flathead screwdriver or something and bend them out a little. Also check video connector at the chassis. Pins can loosen there too.

What game is it? Improper voltage can cause a garbage boot on some pcbs.
 
Get a small jewelers flathead screwdriver or something and bend them out a little. Also check video connector at the chassis. Pins can loosen there too.

What game is it? Improper voltage can cause a garbage boot on some pcbs.

The pins need to be replaced, not just pried back out. Either your power supply is dead or your edge connector is bad or both.
 
well, if they need to be replaced eventually then there's no harm in bending them a little for the time being.
 
while I don't dispute the JAMMA harness pin thing, the coin switches could very well be a ground issue, and the monitor itself could have cold solder at either the signal header pins or even the color drive transistors.

frankly, I think you should overhaul all of the above. at least then you'll know it's all working right.
 
Hey guys! Its was the jamma harness and the power supply! Although now one of the chips on the knock off Ms Pacman board starting to smoke after the game is powered up. I did notice on the old jamma connector that 2 pins connections were missing compared to the new one I put in it.
 
Hey guys! Its was the jamma harness and the power supply! Although now one of the chips on the knock off Ms Pacman board starting to smoke after the game is powered up. I did notice on the old jamma connector that 2 pins connections were missing compared to the new one I put in it.

I have a dynamo cab that has very finnicky Jamma harness pins. Everytime I switch pcbs I lose either a monitor color or a pushbutton. It needs to be completely replaced but I usually just wiggle it to find the sweet spot :)
 
Hey guys! Its was the jamma harness and the power supply! Although now one of the chips on the knock off Ms Pacman board starting to smoke after the game is powered up. I did notice on the old jamma connector that 2 pins connections were missing compared to the new one I put in it.

2 missing pins doesn't necessarily mean anything. What were the 2 pins? Could have been a ground removed, extra button etc...

If you're not sure, here a quick pinout to identify. (bottom of page)

www.arcade4home.com
 
Update with PICS:

After looking both jamma harness's over the power supply plugs were not identical. The faulty harness had the yellow and white pins reversed compared to my good harness. I swapped those and bravo no more board smoke. The game plays fines although the sound don't work I tried turning the volume up and got nothing .... I tried another pcb and the sounds plays fine so no more wiring issues. After looking the board over it wasn't a chip that was smoking but a "transistor" Model #TDA2003-89S2 next to the volume pot. Its toasted and that's all the numbers I can read on it. Like I said its a knock off pcb here's the info on the board. Electronics KM-001. Anybody got info on this pcb or one like it for sale? The vid and game roms seem fine although I don't know about the sound roms. Pics are attached! Any help or ideas on this one?

Everybody thanks for all help and advice thus far!!!
 

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