Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: meary on April 29, 2009, 01:38:36 am
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Hi,
I've got a dead monitor which I believe is a WG K4906. I'm starting to think that it might be a power supply problem, but hopefully someone here can help me figure that out. This is my first time working with a monitor so hopefully this makes sense. The game is making sounds and playing fine, and I don't have any glow at all coming from the tube. When I tested the power going into the chassis I get 15v, which seems too low. I hardly get any reading at all at regulated power supply R503, which according to the flowchart should give me +130 VDC.
I haven't been able to get any readings out of the power supply, but I'm not totally sure how to go about testing that. Any help with this would be great! Here are some pictures I took.
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So you are only getting 15v at the two points I've circled ?
(this should be around 115v AC)
And either it's an optical illusion or I just don't see the rest of the power cord in that same picture.
Can you follow it down from the monitor to the bottom of the cabinet?
Should lead down towards that transformer somewhere.
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Yeah those are the points that I was testing. I guess that's my problem then. Thanks for the help! Now I guess I need to figure out where the power is going wrong. You can see the cord a little better in this picture, it does lead down to the bottom.
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Unplug the monitor from the cabinet and meter the power from that cord. If it's still odd follow the cord down. Check your fuses. If this is an old Midway cab their fuse holders are crap, and can account for low voltage.
Assuming that things check out okay, however, I note the chassis is a bit dirty. A bit of grunge can interfere with accurate readings. WITH THE POWER OFF get a cotton swab wet with alcohol (99% if you have it) and clean those two points mentioned, then take a reading again. You may have to move the tips of your meter around a bit to get a good reading. Don't be afraid to get right in there and push a little bit, but DON'T slip!
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Thanks for the help! . I think I was just getting bad readings before. The power is ok, but the fuse is out. That should be simple enough. What's worrying me though is that the green/yellow wire (ground I'm guessing) is just hanging, not connected to anything. Should this be attached to something?
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That's earth ground. Should be connected to the frame of your monitor. Not necessary to run it, but a good idea to have it connected.