Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: speed_of_bokchoy on January 25, 2006, 11:59:11 pm
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As the title states, I have a Wells 19K4906, no green. Changed the three transistors as per the flowchart, nothing. Cap kit, nothing.
What I was wondering is there any other tests I should do? I was thinking of switching the red and the green just to see if perhaps the CRT isn't getting a green analog signal from the chassis? Tried a known working JAMMA board as well.
Thanks in advance,
Jay
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Make sure the green color control pots on the neckboard haven't been somehow turned all the way down first.
It is possible that the picture tube may have an internal problem too.
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Can I switch the input to the CRT (lets say, use red or blue, which I know are good) and see if green works? If it does, that means somewhere before the CRT is my problem, and if no green at all still, then CRT.
Thanks
Jay
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yep swap the colour input,this will prove the signal from the gameboard is running,if i remember correctly the 4000 series chassis suffered badly from heat problems on the neck card(think i got the right one),i think there are 3drive transistors on that card perhaps the green drive transistor is shot or the track around it is broken ,also 3 large resistors,if thats all ok then you could be looking at a gun fault in your tube,also make sure that there are no bent pins ot the tube itself.
did the fault just happen or did you buy the monitor like it?
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Swap the color signal inputs at the connector on the monitor mainboard that comes from the gameboard.
It's the model D9200 that suffered from a poorly designed neckboard where the transistors and resistors burned up.
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Checked VR404 and VR402, seemed within specs. Swapped red/green inputs to neck board, still had red, so green input is good. Checked R411 (15K) checked out good.
I think it may be internal in the CRT :(
Anything else I should try/check?
Thanks
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It may not be a neckboard transistor causing the problem but a transistor on the main chassis 2n3904 or the capacitor associated with it.