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-   -   Is there a general guide for common failures and repairs of LCD sets? (http://www.videokarma.org/showthread.php?t=277157)

AlanInSitges 02-14-2025 04:31 AM

Is there a general guide for common failures and repairs of LCD sets?
 
I have a 75" Toshiba that has started to intermittently power on with the backlight missing down one side. Some days yes, some days no.

I have no experience with modern sets at all and wonder if there is a sort of general troubleshooting guide for these? Backlights seem to be a common problem area.

jhalphen 02-14-2025 10:30 AM

Hi to all,
Hi Alan-in-Sitges,

Probably one or several shorted white LEDs in a strip which then goes dark.
or a power supply unit which conked out (bulging caps, shorted switching FET)...

LED strips can be purchased cheaply on AliExpress, BangGood, etc. but the repair requires skills :
a large table to lay the screen out flat.
delicate "Spudger" work to open the bezel without breaking plastic tabs.
then you have to very carefully "peel the layers", protection screen, front polarizer, LCD panel, rear polarizer, rear holographic light diffuser.
only then can you access the rear "bathtub" where the LED strips are located.
then finally, all the same operations in reverse to reassemble.
The 75" glass LCD panel is millimeters thick and extremely fragile, you'll need at least one person to help you manage the panel.

Replacement LED strips must be exact model or at least same # of LEDs/strip, power rating, etc.
OEM TV manufacturers unfortunately have a bewildering array of models, sizes, # of LEDs/strip, etc.

I have several modern pdf books written by a Mr Jestine Yong from Taiwan describing the repair of LCD monitors (usually computer displays) and the SMPS power supplies that drive them.
Yours for the asking, send me your Mail via PM if interested.

From memory, our member ElectronicM does repairs on flat panels, there may also be others,

Best Regards
jhalphen
Paris/France

AlanInSitges 02-14-2025 03:56 PM

Thanks very much Jerome! I've sent you a PM.


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