Toshiba Regza 57Z3030D dark patch on screen when cold

[TrustyBear]

I have a Toshiba Regza 57Z3030D, when cold, there is a dark patch down the centre of the screen, not blank, but darker than the outer edges.

As the set warms up, (about 30 mins) the screen flickers, and the image becomes perfect.

I have checked the psu outputs and they all seem within tolerances.

where to look next, inverter, ccf tubes, main logic?

Has anyone any experience on large Toshibas who could guide me the right way?

[tom66]

Re: Toshiba Regza 57Z3030D dark patch on screen when cold

This is a classic case of bad tab bonds. It's sometimes, but not always fixable. The LCD panel is faulty and this is a very expensive part.

http://www.youtube.com/watch?v=zW998RTAq-0
http://www.youtube.com/watch?v=vCExlSnG4yY

The same problem manifests itself in different ways. Sometimes you can get dark patches which warm up and the TV behaves fine. Other times, one side is permanently slow to change and does not work properly.

A simple way to verify the diagnosis is to apply a little pressure to the top of the TV and see if the picture fixes itself.

[TrustyBear]

Re: Toshiba Regza 57Z3030D dark patch on screen when cold

Thanks for that, it looks like that could well be the problem.

I will post back when I have tested the tabs.

[TrustyBear]

Re: Toshiba Regza 57Z3030D dark patch on screen when cold

Just a thought, but could a Philips 32PFL5522D/05 that shows a red screen when cold, and comes right after about 30 minutes be the same thing?

[tom66]

Re: Toshiba Regza 57Z3030D dark patch on screen when cold

Just a thought, but could a Philips 32PFL5522D/05 that shows a red screen when cold, and comes right after about 30 minutes be the same thing?

Quite possibly. I had a Philips TV with a similar problem to your Toshiba but not that bad, as it cleared itself after about 2-3 seconds.