Re: toshiba 50L1350U no backlight
One set of 5 LEDS are bad. I applied 15 vdc to each string of 5. I ordered the new strip. Looks like my test boxes with 36 lights caused the same fault as having a bad LED. When I get the new strip and get everything back together I will remove 6 lights and retest.
Shatch
Member
Last Activity: 08-12-2018, 10:09 AM
Joined: 11-10-2012
Location: Hanover,PA
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Re: toshiba 50L1350U no backlight
I replaced the power supply board and the mainboard, no change. I took the back off the screen. There are 60 LEDs. 30 LEDs per string. I had 36 on each of my test boxes.Leave a comment:
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Re: toshiba 50L1350U no backlight
Yes. It starts at about 3.2 volts ,drops to 1.7 volts, then mv .Leave a comment:
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Re: toshiba 50L1350U no backlight
...Leave a comment:
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Re: toshiba 50L1350U no backlight
I'm having trouble with getting the pic posted.Leave a comment:
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Re: toshiba 50L1350U no backlight
I hooked up two separate units. I unplugged the LEDS to the TV screen, and soldered the wires to L1+ ,L1-, and the other to L2+ and L2-.Leave a comment:
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Re: toshiba 50L1350U no backlight
I bought LEDS on ebay. I made two little wooden boxes up. Each box I drilled 36 holes. The LEDS are 3 to 3.4 volts. Someone posted the voltage to be 117v. So 36 would give me 108 to 122.4 volts. I hooked them up and turned the set on. The lights flash and go out. The lights stay out until I turn the set off, then they flash. Any ideas to eliminate the power board or the mainboard ?Last edited by Shatch; 03-08-2016, 03:12 PM.Leave a comment:
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Re: toshiba 50L1350U no backlight
I want to thank everyone for their help. I will try a bunch of LEDs to load test it. I'm working on this for a friend and trying to keep the cost down.Leave a comment:
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Re: toshiba 50L1350U no backlight
Yes I'amLeave a comment:
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Re: toshiba 50L1350U no backlight
I'm thinking it's either the main board or the lights themselves.Leave a comment:
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Re: toshiba 50L1350U no backlight
Thanks for the response budm. I tried removing the PWM wire and applying 3.2 volts . It didn't help. I guess I need it pulsed. I trying to think what I have to get 110 to 120 volts DC to test the lamps.Leave a comment:
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Re: toshiba 50L1350U no backlight
I have BL_ON and PWM on start. Backlights flash. PWM drops to 232mv. No Backlights. I removed the PWM wire and the backlights don't flash on. L1 and L2 is at 77 volts. At first it is 110volts then drops down as the PWM drops out. Any ideas to eliminate good from the bad ? The power supply voltages all look great. Any ideas to test the backlights themselves ? Thank youLeave a comment:
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