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Equipment Repairs => LCD TV forum => Topic started by: D.R. on November 23, 2011,15:42:46

Title: LOG26LW782 Logik Display Fault
Post by: D.R. on November 23, 2011,15:42:46

Hi,

I have recently saved a Logik LCD TV from a trip the skip and I'm looking for some advice on how to rectify its fault.

When you switch it on it displays a grey screen for up to 20mins, depending on when it was last switched off, during which you get sound and can switch channels and after which it works perfectly. The grey screen fault can be as little as 3mins or no grey screen if its just been switched of then back on.

I was thinking it was a capacitor charge / discharge issue due to the variable grey screen time and rather too eagerly re-caped the PSU to no avail but after reading several posts I am leaning towards a faulty T-Con board.

I cant find a service manual for the TV so if anyone can suggest places to look it would be appreciated. I'm an Electrical Engineer (but not a TV Eng) so feel free to suggest a place or two to poke around with a multimeter.

I've found a place selling the correct T-Con board for £35 but I'd rather fix it if at all possible. Any help would be much appreciated.

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on November 23, 2011,15:49:57

The rest of the PCB photos.

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on November 23, 2011,16:17:10

The main board, part number 17MB22-2, appears to be common to a lot of TV's manufactured by several different companies I found a Vestel manual here http://elektrotanya.com/vestel_17mb22_2_sm.pdf/download.html not had a chance to take a really good look at it but it looks promising.

The T-con, part number V260B1-C01, also looks widely used with listings for new boards from China on e-bay.

Title: Re: LOG26LW782 Logik Display Fault
Post by: Turnip on November 24, 2011,12:17:52

Hi D R,

Got several of the Tcon you mention from screen smashes - cheap. If you think it's not the screen will post you one - Chris.

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on November 25, 2011,01:16:36

Quote from: Turnip on November 24, 2011,12:17:52

Hi D R,

Got several of the Tcon you mention from screen smashes - cheap. If you think it's not the screen will post you one - Chris.

PM'd you.

Title: Re: LOG26LW782 Logik Display Fault
Post by: Turnip on November 25, 2011,12:01:46

Hi DR,

Answered with a cheapy T-con, but have you tried twisting the screen from the top with fault present, duff screens are really common - Chris

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on November 29, 2011,11:20:19

Quote from: Turnip on November 25, 2011,12:01:46

Hi DR,

Answered with a cheapy T-con, but have you tried twisting the screen from the top with fault present, duff screens are really common - Chris

Still havent got round to fitting the T-con, I'll post the results as sonn as I have.

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on December 01, 2011,14:26:20

It looks like the screen is indeed faulty. If you apply pressure to opposite top and bottom corners when its mounted on the wall the picture immediately appears.

Short of replacing the screen or binning it is there anything that can be done?

Title: Re: LOG26LW782 Logik Display Fault
Post by: D.R. on December 01, 2011,14:46:31

O.K. so after searching "pressure" it seems I've answered my own question above. Looks like I'm going to be taking it apart and applying some pressure to the screen connectors with bits of foam / rubber.

I'll let you know how I get on...