"Chuck" wrote in message
...
On Sun, 26 Feb 2017 14:06:31 -0800, John Robertson
wrote:

I have an older monitor from a video game - and it has a jitter on the
horizontal lines on the screen (vertical is locked), yet I don't see
this jitter on the H Sync. Using a signal generator (Cross-Hatch, Dot,
etc.) and all outputs are the same. Game source also shows same jitter
on same screen.

It is not the WICO monitor signal generator as other B&W monitors show a
locked image.

Schematics he

http://www.flippers.com/pdfs/TEC_TM-...23_Monitor.pdf

Monitor has been recapped. Horizontal does lock, but jitter still present.

Suggestions appreciated!

Thanks,

John :-#)#

If the problem isn't HV arcing, check or replace parts from pin3 of
the flyback including the 2 AFC diodes D401 and 402. The diodes on
this line I'd just replace.

A dry joint is also possible, or a noisy part burned resistor dropping
feedback from a flyback winding to the phase discriminator.

Arcing usually isn't too hard to see - corona discharge can be, a faint
purple haze around any sharp pointy bit at EHT potential. Sometimes you have
to view the chassis with the light turned off to see it.