remove this thread

[xy-man]

Hey Ken,
I have worked on WG 6100 for a long time but I haven't come up with this problem. The screen voltage seems to flutter causing the size of the picture or edges of the video displayed to become larger and smaller. This HV cage had blown some transistors, resistors, and had some leaky caps, which I have replaced. Those corrections displayed the known good video I was injecting but I had this expanding and contracting screen/video size so I changed the 25k pot for high voltage. That cleaned up some of the noise in the picture but didn't get rid of the constant fluttering of size. I can best see it the in the text on the edge of the screen because it should stay still or fixed. The sizing dots in the corners don't seem to be effected by the fluttering they stay steady in their locations. I know that the problem is in the HV board because the swap for a known good HV cage didn’t display this symptom the problem. I hope that you can shoot me an idea or two. Thanks. 

[grantspain]

I thought Ken was in trouble when i saw this post

[BASS!]

Lol! me too. I was thinking he was in jail or something.

[SirPeale]

Changed the thread title because I thought the same thing!

[Ken Layton]

I haven't worked on xy monitors in a good 25 years. They gave me so much grief I never want to see another one as long as I live.

From what I remember, those damn high voltage diodes (stick rectifiers) in series with the high voltage lead from the flyback to the tube had problems. Generally the connections inside those thick rubber boots with the spring tension pushing against the rectifier corroded/tarnished causing flucuating high voltage. The cure was to install a new rectifier, but instead of relying on spring tension to make contact, carefully unfold the leads on the rectifier. Now take those ---smurfing--- springs out of the rubber boot and throw them away. Strip the wire ends on the high voltage wire and hook to the new rectifier. Be sure to silicone glue the soldered area to keep from arcing!

Pay attention to the diode polarity too.

[Kevin Mullins]

I originally thought about the diode first thing as well. But wasn't sure if the 6100 even had those. (I've only worked on the GO5's and such) And since he had tried a second HV assembly, then the original one could very well have a corroded spring as Ken said.

And them damn diodes are getting spendy I might add..... like $15.00 the last time I shopped for one. (I believe Bob Roberts still has them)

But check the HV lead coming off the flyback first of course.

[Kevin Mullins]

"remove this thread" ??

What for?
A solution to your problem could very well be a solution for someone else.

[SirPeale]

Agreed.  Thread stays.