UPDATE: Panasonic TV Model CT-27SL13G, Odd Symptom
 

Hi,

I can't remember how long it has been since I saw a yoke with an open
winding (extremely rare in my experience), but one of the two vertical
deflection windings (in parallel) is open!

I had to unsolder and separate the leads in order to make the
test. At this time, I am not sure if the customer is willing to spend
the money to have this set repaired since the yoke is very expensive.

Brad

On Thu, 16 Nov 2006 18:57:40 GMT, (Brad) wrote:

In my service shop, I have a Panasonic TV model CT-27SL13G (mfg 07/03)
with an odd symptom. The picture is about 6 inches high (black on top and
bottom), but it is "warped" with a wavy edge (top & bottom).

I checked electroylitics in vert. circuit. Regulated B+ is 130V, there
is +27V at pin 2 (VCC) of IC451 (AN5522). I scoped pin 2 looking for
excessive ripple, but found around 2V P-P ripple. I "rang" the yoke with a
yoke tester (ok) even though I didn't think it is the cause. I replaced
IC451 (AN5522), but the problem remains. It may be a problem in the yoke
return (I have no schematic)? Did you have a problem like this?

Thanks in advance, Brad

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