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From: Rob on 2 May 2006 20:10
I have replaced the LA7841 vertical output ic and got the unit back up
and going again, but the ic is getting too hot and vertical linearity is
not good. The top part of the picture is fine, but the very bottom is a
little compressed. Possibly yoke short? I did find some bad caps in
vertical section and it did correct some of the problems. Just wondering
if anyone has run into this before on this series of set?
From: electricitym on 2 May 2006 23:31
Rob:
You probably missed a cap or two.... re-check your work. If you
suspect the yoke you should ring-test it.
electricitym

From: Leonard Caillouet on 3 May 2006 09:03
How do you ring test a vertical yoke? Every one that I have ever tested has
no more than 4 rings with either of 3 Sencore units that I have. I have
never found this to be an effective way of evaluating vertical yokes. How
do you do it?

If a yoke is working and the problem is linearity, the problem is almost
always going to be a bad cap.

Leonard

<electricitym(a)yahoo.com> wrote in message
news:1146627087.035090.276420(a)v46g2000cwv.googlegroups.com...
> Rob:
> You probably missed a cap or two.... re-check your work. If you
> suspect the yoke you should ring-test it.
> electricitym
>


From: electricitym on 3 May 2006 10:20
Leonard:
If you ring-test a yoke with a shorted turn and compare the results
with a good yoke you can see the difference immediately...... a yoke
with a shorted turn will have lower amplitude rings and be quite
obvious when compared to a good yoke. I always keep a good yoke handy
in my junk box for this reason.
electricitym
..
..

From: Rob on 3 May 2006 20:06
Leonard Caillouet wrote:

> How do you ring test a vertical yoke? Every one that I have ever tested has
> no more than 4 rings with either of 3 Sencore units that I have. I have
> never found this to be an effective way of evaluating vertical yokes. How
> do you do it?
>
> If a yoke is working and the problem is linearity, the problem is almost
> always going to be a bad cap.
>
> Leonard
>
> <electricitym(a)yahoo.com> wrote in message
> news:1146627087.035090.276420(a)v46g2000cwv.googlegroups.com...
>
>>Rob:
>>You probably missed a cap or two.... re-check your work. If you
>>suspect the yoke you should ring-test it.
>>electricitym
>>
>
>
>
Thanks for all the help on the vertical problem, I seem to be finding a
lot of dried up caps. I think where unit was located, it didn`t have
much ventilation and it had alot of dust. Rob
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