Motorola VT-71/TS-4J
 

Have been working on this one for a few days now. Have a raster with picture but it also has bars across it. What do you think the cause is? I've replaced most of the caps and a lot of resistors.
Terry

Did you put the high voltage cage back on?

Don

Yup it's on but I don't have the aluminum shield on the crt. I'll give that a try. You think it's rf interferance?
Terry

Sure looks like it, the electrostatic sets are pretty sensitive to that type of interference.

Put the crt shield on but didn't make any difference. Did notice that the HV cage isn't at chaiss ground or B-. It's at RF ground though a 470k and .1 cap +100ohm resistor. All ok. Guess it's time to go play cards with my 9yr while I mull it over.
Terry

TS-4 problem solved (I think)
 

I think the problem was that the HV p/s cover was touching thee ground strap around the 7JP4. On these set that cover have it's own ground and it's not the same the crt and speaker. There is a piece of insulating paper under the HV cage were it mounts to the chaiss.
Those bars where making me crazy, I think this has got it.
tnx for help!
Terry