RED MONITOR!!!!????--help--

Tung Fu ru · Apr 29, 2007

I just recently received a FREE

JAMMA cabinet with a 20" monitor and the machine works, except that the monitor is all red, with nothing else on the screen. I fiddled with the knobs on the back of the monitor but no change, I also tried a few different boards with no change also.

Anyone know what's wrong with the monitor/cabinet?????

channelmaniac · Apr 29, 2007

Check the wires from the JAMMA harness to the monitor...

Check the input connections on the monitor. Wiggle them and see if the color comes back. The solder joints may be cracked.

Beyond that, resolder the input connector and the CRT socket on the monitor. If that doesn't do it then it's time for some advanced troubleshooting.

RJ

ttooddddyy · Apr 29, 2007

Disconnect the R, G and B drives to the CRT base PCB. If you still have all red then the problem is on the red video output stage. Possibly dry joints or a short on the output drive transistor. If you are unlucky it may turn out to be the CRT itself (short or leak between red cathode and heaters) - chances are that it is something else though

channelmaniac · Apr 29, 2007

If it does end up being a short in the CRT those can sometimes be fixed with a CRT Tester/Rejuvenator... A local TV repair shop should have one. You'll have to call around your area to see...

Tung Fu ru · May 1, 2007

Thanks for the help so far,

I checked the cab today and checked the wires going from the JAMMA harness to the Monitor, they seemed fine, and I tried moving around some wires and stuff but saw no change so I don't think it's the connections.

I really don't know very much about electronics or fixing monitors so this is confusing to me:

ttooddddyy: "Disconnect the R, G and B drives to the CRT base PCB. If you still have all red then the problem is on the red video output stage. Possibly dry joints or a short on the output drive transistor. If you are unlucky it may turn out to be the CRT itself (short or leak between red cathode and heaters) - chances are that it is something else though"

how do I know which wires are the R, G, and B drives and how do I disconnect them?

SSS · May 1, 2007

check the B/G pins on the connector to the chasis from the jamma connector. One of the cabs I got was not displaying red, turns out the pin in the connector had been bent back and was not connecting to the pins on the monitor board.

you could also trying removing just the red wire, if the image totally disappears, that could mean no blue or green signal is being sent.

ttooddddyy · May 2, 2007

Tung Fu ru said:
ttooddddyy: "Disconnect the R, G and B drives to the CRT base PCB. If you still have all red then the problem is on the red video output stage. Possibly dry joints or a short on the output drive transistor. If you are unlucky it may turn out to be the CRT itself (short or leak between red cathode and heaters) - chances are that it is something else though"

how do I know which wires are the R, G, and B drives and how do I disconnect them?

They are usual coded to match the drive, so the red wire will be the red signal from the monitors mother board to the CRT base board.

If you are not familiar with this sort of thing maybe best not mess around with it as there are some high voltages around that area.

Ruell · May 5, 2007

hmm.. I have a monitor that's all green instead of red. I'll have to get it out of the garage though and let it sit inside a few days before messing with it. just to be safe with condensation blah blah.

RabbitTroop · May 7, 2007

The monitor probably just needs a cap-kit... is it dim at all, or bright red?

Tung Fu ru · May 14, 2007

nruva said:
The monitor probably just needs a cap-kit... is it dim at all, or bright red?

bright red, with no other colors on the screen

channelmaniac · May 14, 2007

Can you see any of the game graphics on the screen or is it just a full red screen?

RJ

Ruell · May 14, 2007

Woahh. Haven't messed with the monitor in a while. After tweeking a little though, it turns out there's no blue. The other colors work though and the blue turns out greyish usually. I've tried also toggling with the blue bias and it changes the contrast, so I guess it's not the toggle, but maybe a resistor/transistor or something. It's a Wells Gardner K7400 series I think.

Tung Fu ru · May 16, 2007

channelmaniac said:
Can you see any of the game graphics on the screen or is it just a full red screen?

RJ

red screen only, you can't see any of the graphics, but you can hear the sound

channelmaniac · May 16, 2007

That typically points to a shorted driver transistor on the neck board.

RJ

Tung Fu ru · May 17, 2007

I took another look at the cab today and found a bunch more knobs that I didn't notice before. After fucking around with a few of them, I could make out a picture!!!

So since then I've been tweaking with the knobs trying to get the colors, brightness/contrast and all that stuff right. But aside from the colors looking dull or washed out, there are lines going through the screen and the screen is upside down.

Do I need a cap kit? And how do I flip the screen back to normal?

RED MONITOR!!!!????--help--

Tung Fu ru

Actual Musician,

channelmaniac

Mr Neo Fix-it

ttooddddyy

PNG FTW,

channelmaniac

Mr Neo Fix-it

Tung Fu ru

Actual Musician,

SSS

neo retired

ttooddddyy

PNG FTW,

Ruell

, I FORGOT MY SECRET SANTA OBLIGATION. FUCK ME, RI

RabbitTroop

Mayor of Southtown, ,

Tung Fu ru

Actual Musician,

channelmaniac

Mr Neo Fix-it

Ruell

, I FORGOT MY SECRET SANTA OBLIGATION. FUCK ME, RI

Tung Fu ru

Actual Musician,

channelmaniac

Mr Neo Fix-it

Tung Fu ru

Actual Musician,