Model LN52A650A1FX2A
A section on the lower right side becomes blurry and ghosty. Intermittent on startup and goes away in about 5-7 minutes.
Know something about electronics, old tube guy, and have equipment.
Any suggestions would be greatly appreciated.

On Sunday, November 25, 2018 at 8:47:41 PM UTC-5, Ivan Vegvary wrote:
Model LN52A650A1FX2A
A section on the lower right side becomes blurry and ghosty. Intermittent on startup and goes away in about 5-7 minutes.
Know something about electronics, old tube guy, and have equipment.
Any suggestions would be greatly appreciated.



Easy. Bad display. Could be a bad IC on one of the ribbons or bad ribbon bonding between the address board and display. If it's bonding, you can sometimes stuff some soft foam between the offending ribbon and the display frame, but anything you do is a temporary solution.

You can live with it or replace the TV.

Flex it. If it clears up try a shim, like card stock or something to keep the pressure on it.

Sometime it is hard to discern if a fault is in the panel or the Tcon, but in this case it is in the panel. you might have to loosen a screw or two and stick something under the panel to stress it and keep the connections alive.

Also flex all those little ribbons, they might be hard to get at but most of them have COB (chip on board) and sometimes that is what you need to stress.

It is is all you can do other than sell parts. You might be able to get Shopjimmy to buy them, or you can put them on eBay. At least you can say you know they're good.

It seems to be a problem of magnetic field (magnets, loudspeaker... nearby)

In those old TV there was a demagnetizing bobin for demagnetizing the
screen.
It was generally fed with mains through a PTC and a PTN or two PTC.
after some minutes, this circuit is off.

I suppose you get a prblem with this system (Bobin open-circuit ? ).

This bobin is generally in a plstic tube which is rectangular formed and
placed near the edge of the CRT (take care of the VHV, THT in French).

After some minutes, the CRT is demagnetized even if this bobin doesn't
work ; this is due to te electrons sweeping, but it is "a long time" for
the viewer.

You should check the wiring of this bobin

Sometimes the PTC(s) and/or PTN (in a plastic "box" with 3 pins) are
cracked because of their age. you should look for the common pin and
then check each resistor.

Heating this part should increase one and decrease the other or increase
both of them.

Send me a message with your E-mail, I will send you the classic system.



Ivan Vegvary a écritÂ*:
Model LN52A650A1FX2A
A section on the lower right side becomes blurry and ghosty. Intermittent on startup and goes away in about 5-7 minutes.
Know something about electronics, old tube guy, and have equipment.
Any suggestions would be greatly appreciated.

The model umber indicates it is an LCD TV.

You talked about gaz tube.

If it is a LCD, no issue, the mosaic or the back-light is dying.
It could be a miscontact in the flat ribbon cable, but I don't think
(check it).
The back-light is generally fed apart with its plug.
If you open, you can check the back-light.
But I think you have problems with the data cable.
You will need a microscope or a viewer for that check.

The question : did it come suddenly or gradually ?

a écritÂ*:
The model umber indicates it is an LCD TV.