4900 shadow

Sgt.Rocks

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I have a 4900 monitor with a shadow on the right side of the screen,I changed c702 and it got rid of the dark screen on the left side,but the shadow is still there
 

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Many people have mentioned this problem (in my searching) and given things to try, but no one has ever come back to say whether it worked or not.

You may have a problem with the internal shadow mask. if so, then get another tube.

You could try replacing C507 (and the rest of the caps) to see if it helps.

And measure the B+. I found a reference on a TV repair site that talks about this problem. if you have B+ that is a little high (but not high enough for HV shutdown), then:

The low voltage regulator is an analog type with a pass transistor that is probably leaky, causing the high B+. Changes in line voltage and loading (with brightness changes) cause the partially blanked picture to change (the black blob moves around, sometimes blanking the entire screen). When you replace the defective component, reset the (B+) with the pot (not possible with a 4900), and you're back in business.
 
I change the tube and still have the same problem.I flippped the yoke upside down and it moved with the yoke,so does any have a yoke forsale??
 
I flippped the yoke upside down and it moved with the yoke,

And it should.....

Have you replaced any more caps yet ?
This is generally a cap issue.
C702 would be the first I'd look at, which you said you changed, but what value was the old and new cap?
 
It is not the yoke.
Check the caps over in the middle to left middle of the chassis. I believe that is where you problem is. I will see if i have documentation on that.
Turning the yoke and it moving tells you only that the yoke is working and the problem is in the scanning still.
 
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