WG 19K7302 wavieness

[kardenm]

I have a WG 7302 which is working well except there is some wave motion/undulation in the lower half and left side of the picture.  It's not real pronounced and at first I thought it was just my eyes (hangover maybe) but its still there. 

Is this likely a cap problem?  Can anyone narrow it down for me? 

Any suggestion are appreciated!

[smalltownguy]

pics / video plz

[Tenn_pin]

First check all ground straps and make sure dust or corrosion is not limiting the connection.  Second, make sure there is a ground wire from the coin door, game board, and monitor, that runs to the transformer ground. Third, remove the starter and bulb in the marquee.  Fourth, check the B+ voltage. Fifth, reflow all of the solder joints.  And finally, install cap kit.

Good luck,
Randel

[kardenm]

pics / video plz

Video will take some time. My camera is broke! Dropped it 30 feet out of the treehouse I built this summer. I'd have to borrow someone's. But I'm suspecting caps.

First check all ground straps and make sure dust or corrosion is not limiting the connection.  Second, make sure there is a ground wire from the coin door, game board, and monitor, that runs to the transformer ground. Third, remove the starter and bulb in the marquee.  Fourth, check the B+ voltage. Fifth, reflow all of the solder joints.  And finally, install cap kit.

Good luck,
Randel

Monitor not installed in cabinet.  Trying to shortcut all that anyway. But thanks for your input. I am  checking solder joints and B+ voltage.

[smalltownguy]

I'm working on that exact same chassis, so I'm very familiar with it these days. If you're going to do a cap kit, let me know, because the Bob Roberts cap kit may not meet your needs. It's been documented that his cap kit was built on a specific revision of that chassis, and there are several revisions. You may need to build your own cap list.

[kardenm]

I am replacing some caps. I don't usually order cap kits as I have a large collection of caps on hand.  I pull and test and replace caps as I go, starting with the largest.  I have also worked on this particular model a few times and pretty familiar with it. I will at this point just keep replacing caps and see if the problem goes away.

Thanks again for your input.

[kardenm]

Still have not solved this problem.  I have waves of slight (shape) distortion which move from bottom to top across the width of the picture about half a second apart.  I don't think this would be visible on a posted video even IF I had a video camera to capture it with. 

I called tech support at WG and was suggested I check or replace the filter caps (801,802), which I did even though the old ones tested good.  I have also replaced the thermistor/posistor (R801) and various other electrolytic caps, a couple of which were a little low in value.  But, no luck yet.

Anyone have any more suggestions?

[smalltownguy]

I have one

[grantspain]

could be cab earth interference,some psu like the ground and earth linked
otherwise it could be a fault on the degauss circuit-you could prove this by just disconnecting the degauss coil

[kardenm]

I have one

I like your suggestion the Best!  But the boss probably will not. 

could be cab earth interference,some psu like the ground and earth linked
otherwise it could be a fault on the degauss circuit-you could prove this by just disconnecting the degauss coil

Tried disconnecting the degauss coil like you suggested, still looks the same. 

[kardenm]

Problem Solved.  Found the culprit! Was small cap#812 (220uF/25v) which tested at 50uF.  Replaced it and all is good.  Boss is happy!

[smalltownguy]

Where was that cap? On the main board, or the neck board?

[kardenm]

On the main board.  I did check the one electrolytic cap on the neck board but it was fine.

[codecrank]

I had a similar issue with my first monitor. The BYOAC regulars helped me fix it.  I installed a cap kit and main filter cap.

http://forum.arcadecontrols.com/index.php?topic=101332

man I was so happy after fixing it, amazing feeling 

[kardenm]

Cool.  "I love it when a plan comes together"!