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Screen VES315WNDL-01
Turnip:
Hi folks,
Just got a Sharp LC32LD145K with sound but no backlight. Notice backlight uses just a pair of leads so guess all strips in series, although that represents rather a lot of volts
Checked voltage from 17IPS19-5 reading 25v where surprisingly the Black lead was positive. Tried a string tester and at 20m/a got a max reading of 17.5v.
Suspect a huge number of S/C diodes - Chris.
Davy:
The LED driver board isn't behind the screen by any chance? I was 'foxed' once, the two wires carried about 24V DC for the board.... I expected a third wire for the PWM brightness control, mind you it wasn't a Sharp, thought I'd just mention.
Dave
Turnip:
Thanks Dave,
Thought take it apart finding two series strings of 11 Leds with the first Led on each string S/C.
Curious thing, when I then connected the 'String Tester' all but the duff pair lit up. Odd as I'd checked the voltage from 17IPS19-5 (25v) and also with the string tester when disconnected from supply (17.5v) - Bit odd, might well have a supply issue if it can suss just two duff diodes out of 22.
Next problem is that the strips are really well stuck down, and lenses pop off when I try lift, even with a certain amount of hairdryer heat.
Tend to suspect flexing also liable to offend the good diodes - Maybe rip strips out and replace all diodes.
At 10p per genuine LG diode - £2.20 is cheaper than £46 for a new pair of strips - Much more fun too if you have the time - Chris.
vinceroger69:
--- Quote from: Turnip on March 27, 2017,11:25:55 ---Thanks Dave,
Thought take it apart finding two series strings of 11 Leds with the first Led on each string S/C.
Curious thing, when I then connected the 'String Tester' all but the duff pair lit up. Odd as I'd checked the voltage from 17IPS19-5 (25v) and also with the string tester when disconnected from supply (17.5v) - Bit odd, might well have a supply issue if it can suss just two duff diodes out of 22.
Next problem is that the strips are really well stuck down, and lenses pop off when I try lift, even with a certain amount of hairdryer heat.
Tend to suspect flexing also liable to offend the good diodes - Maybe rip strips out and replace all diodes.
At 10p per genuine LG diode - £2.20 is cheaper than £46 for a new pair of strips - Much more fun too if you have the time - Chris.
--- End quote ---
Have you got a link to genuine lg leds at that price or is it just through trade etc
Turnip:
Hi Vince,
Mentioned the Leds on quuq a few weeks ago. Think they're still listed as -
100-500-1000pcs-High-Power-LG-110LM-1watt-3528-LED-Backlight-Television-Backlit
Used my first new ones today and they looked far better than smashed screen Leds that may work, but seem a bit the worse for wear under magnification - Chris.
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