Help needed with horizontal jitter in Zenith PTV

[dwfincher]

I have a PV4657BG (C3 chassis) that has a horizontal jitter problem.
It is in small bands (usually 2) that move slowly up the screen. A
typical vertical line would look something like:

|
|
S
|
|
|
S
|
|

Where the S's are the slight wiggle of the horizontal line. These
would move up and off screen with a new one starting close to the
bottom when the top one moves off. The power supply looks good on the
scope with minimum ripple.

Any ideas?

 

[Arthur Jernberg]

Disconnect the cable souce from the tele, if the noise bar goes away while
playing a vcr or dvd with the cable line disconnected the problem is not in
the tele.

 

[Patch]

I have a PV4657BG (C3 chassis) that has a horizontal jitter problem.
It is in small bands (usually 2) that move slowly up the screen. A
typical vertical line would look something like:

|
|
S
|
|
|
S
|
|

Where the S's are the slight wiggle of the horizontal line. These
would move up and off screen with a new one starting close to the
bottom when the top one moves off. The power supply looks good on the
scope with minimum ripple.

Any ideas?

Sounds like a leaky electrolytic cap in the vertical output stage.

 

[Jerry G.]

This still sounds like a noise from the supply or a ground loop. Disconnect
the cable, and see if it does this with an independent source.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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I have a PV4657BG (C3 chassis) that has a horizontal jitter problem.
It is in small bands (usually 2) that move slowly up the screen. A
typical vertical line would look something like:

|
|
S
|
|
|
S
|
|

Where the S's are the slight wiggle of the horizontal line. These
would move up and off screen with a new one starting close to the
bottom when the top one moves off. The power supply looks good on the
scope with minimum ripple.

Any ideas?