k4903 Yoke resistance

mgb

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Ive got a K4903 that I suspect has yoke damage. I measure 38 ohms on the vertical yoke. It seems it should 55 (Thats what I keep finding online).
Is it correct that the reading should be 55 ohms.
For the horizontal yoke, I read 3 ohms which seems good.
 
Ive got a K4903 that I suspect has yoke damage. I measure 38 ohms on the vertical yoke. It seems it should 55 (Thats what I keep finding online).
Is it correct that the reading should be 55 ohms.
For the horizontal yoke, I read 3 ohms which seems good.

Do you happen to know the yoke part number....should be a sticker stuck to the yoke. There's several different 4900 series yokes. I don't know if I've got any 4903's, but I bet I've got a yoke. Get me the numbers and I'll measure one.

Edward
 
Double check that the battery in your meter is fresh. When you battery gets old/low it can affect the accuracy of what you're trying to measure.
 
I know my battery is good. At the same time I measured that yoke, I measured a G07 yoke and that was fine at 2.5 (horiz) and 55 (vert).
The guy who owns the 4900 actually had a metal file fall into the cab and land across the yoke and rings.
Since then the monitor has been going way bright (not due to the screen adjustment being way up).
So I was suspecting a problem with the yoke.
 
I had an old Taito cabinet to work on today. I opened it up...and what did I see a 4903.

I got 3.1 ohms and 39 ohms.

Edward
 
Hey Elutz,
Thanks a lot for taking the time to check that.
That's about what I got too.
3ohms and 38 ohms.
 
Since then the monitor has been going way bright (not due to the screen adjustment being way up).
So I was suspecting a problem with the yoke.

Can you explain this symptom in a little more detail?

Edward
 
I'm gonna still try and swap the tube/yoke with one I have from a G07. Do you see any problem with that? Just to rehash what happened to this monitor: a metal file fell on the area of the yoke and rings. After that the monitor would start up real bright and over a half-hours time, it would get too bright to even see the game.
On top of, the guy who owns it tried to adjust by turning the convergamce rings. I also am going to check the components on the neck board. I just picked up the monitor the other night and haven't had a chance yet to dig into it.
Am I looking down the correct path with changing the tube and yoke. The monitor also does have a fair amount of screen burn.
 
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