Proscan PLDED3996A-C2 Backlight burnt..

[teeveetroubleddutch]

Hey Badcaps peoples.

Got my hands on one of these quality built Proscan PLDED3996A-C2 LCD tv's

Have picture and sound (picture can be seen with flashlight)

From other threads I found that this model has strips of LED's serving as the backlight for the LCD. Power supply is putting out 25v to the LED connector on top with or without the connector connected. So im thinking it doesn't require a higher voltage to run these? (have several of these strips lighting up my vehicle and they require a welding mask @12vdc..)

Any thoughts?

[R_J]

Re: Proscan PLDED3996A-C2 Backlight burnt..

A picture of the board would help (both sides), Usually the voltage to the led's is higher than 25v. It is usually boosted to a higher voltage around 60 -70 volts
This thread https://www.badcaps.net/forum/showthread.php?t=43429 has a schematic of a led driver supply (most likely different than yours) but should explain how it works.

[teeveetroubleddutch]

Re: Proscan PLDED3996A-C2 Backlight burnt..

Hey RJ

Yes. According to that thread, LED's should have some 70 volts going in their direction. They don't. High voltage part and coil stay cold. Hm. Guess ill be followig the steps in the thread you sent me to see if I can figure out what's causing this.. The connector driving the LED's is the thinner one on top center of the board. Had it set up like this last evening to do some testing.

[teeveetroubleddutch]

Re: Proscan PLDED3996A-C2 Backlight burnt..

Coil doesn't look overheated at all. seen several on here that look like they were barbequed. This one doesn't... and reading through this coil, I should end up with little to no resistance right?

sorry. Have some electronics repair experience, but this may be a bit over my head..