Sanyo 20EZV Nintendo Monitor Problem

[DustyBri]

I purchased this Sanyo 20EZV monitor last week to replace the original Sanyo monitor in my Mario Bros cabinet that had a bad flyback. I used a Zanen Electronics cap kit but it did not fix the problems that the monitor was having. The monitor has a rolling wave that moves through the screen and I need some help in figuring out how to fix it. The smallest part of the wave also seems to be much brighter that the rest of the screen. I have tried all of the adjustments and the only one that makes a significant difference in the shape of the wave is the B+ voltage. The waves get smaller and more numerous when I drop the B+ down to about 75v but the manual I have suggests it should be set at 108v. Mine only gets to 102v max when I adjust VR601 but I don't know if this is related to my problem. The monitor had this problem when I purchased it (I was hoping the cap kit would fix it) so I am pretty sure it is not due to my isolation transformer (the original 100v) or a cap kit mistake. I have also tested the isolation transformer and it is putting out 110v unloaded which is still within the +10% range. Below is a picture of the monitor wave and a link to a short youtube clip of the problem.

http://www.youtube.com/watch?v=ERrxVcyaIH4

Thanks

 

[Warlord]

I would try replacing the main B+ filter cap. When they go bad they can cause a bad wave like that. That would also cause your B+ to be low. Very big cap. Usally around 470 uf or so. If you look at the sqematics its c606 I think. Right after the bridge rectifier. (four diodes right after where the power cord comes in at.)

 

[FullThrottle]

God, that youtube video is giving me either acid or mushroom flashbacks, I can't figure it out!

 

[KenLayton]

You have a bad main filter capacitor. It's the biggest capacitor on the chassis. All capkits do not include this cap. You have to buy it seperately. Zanen and Bob Roberts sell it seperately, but you have to tell them the markings (values) from the original one.
BTW, Arcadeshop sells the reproduction flybacks for the Nintendo Sanyo monitors.

 

[DustyBri]

Thanks for the help! I temporarily borrowed the filter cap from the monitor with the bad flyback and it seemed to make the problem go away. It will still need some fine tuning to fix the colors but I'll wait on that until I order a brand new replacement cap. Then I will get to start to try to fix the Mario Bros pcb and maybe the other monitor too.

In case anyone else needs the info, the filter cap is 470uF 160v 1.5A and has two negative leads.