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Equipment Repairs => LCD TV forum => Topic started by: Davy on May 06, 2017,17:36:21

Title: LG 32LN575V LED backlights
Post by: Davy on May 06, 2017,17:36:21

Got a LG 32LN575V TV, has five rows of 7 LEDs, three are down.... only two strips working. I do think it'd be better to swap all lot and have done, one firm wanted £25 a strip.

Any cheaper sources, to replace all lot I could buy a new telly!

Dave

Title: Re: LG 32LN575V LED backlights
Post by: Turnip on May 07, 2017,11:35:05

Hi Davy,

Had a couple in lately - 32 inch Toshiba Vestel using LG Leds. Found I could easily replace duff Leds from the front leaving the strips in place as could clean either side, use LMP and a wide iron bit to solder both sides at the same time. Wouldn't try it with normal solder though as Leds don't like high temperatures.

The old Leds can be snipped off with sidecutters and the area cleaned up with solder mop and a glass fibre brush. Ten pence per diode and getting cheaper.

Naturally turned backlight down a bit for guarantee reasons - Chris.

Title: Re: LG 32LN575V LED backlights
Post by: Davy on May 07, 2017,12:05:40

Hi Chris, thanks for input.  I did think about replacing the faulty ones but I seemed uncertain about the reliability of the others, can you get them separately or do you have to remove them from used strips?

These LEDs are about the size of a cardigan button. The 70V supply was 'bouncing' so I opened er up.... wonder why they put them all in series, you'd think it'd flash some code or at least blow a 'raspberry'' at ya' but no.

Dave

Title: Re: LG 32LN575V LED backlights
Post by: Turnip on May 07, 2017,12:53:55

Hi Davy,

New LG leds available on Ebay for 10p or less, so now don't bother with old strips as old Leds look a bit crumbly from use.

Most inverters are aware of a single duff Led and cut after a flash, or don't even try fire up.

Agree Leds in Series/Parallel would be more sensible, but think of the amps, thick cables and all those Schottky diode failures - Mind you, Schottky's are real earners on Vestels - Chris.

Title: Re: LG 32LN575V LED backlights
Post by: Davy on May 07, 2017,13:03:23

Thanks for your help, I'll take a shufty on Ebay, agree about the current increase, not just the wires copper tracks too need be wider, meaning more heat as well.

Dave

Title: Re: LG 32LN575V LED backlights
Post by: PROMAN28 on May 19, 2017,08:51:57

HI DAVE I HAVE BEEN SUPPLYING LEDS FOR TV BACK LIGHT OVER 2 YEARS AND THE FIRST GUY TO DO SO ON EBAY IF YOU NEED TRADE PRICES RING THROUGH ON THE PHONE NUMBER ON EBAY GLAD TO HELP  :72:

Title: Re: LG 32LN575V LED backlights
Post by: Davy on May 19, 2017,19:29:46

Will do Proman28, when I getta roundtooit, shelved it for the mo, thanks.

Dave