Author Topic: Toshiba 46TL963 no backlight (Read 8447 times)

old tvman · « **on:** October 22, 2015,06:58:16 »

Anyone ever resolved this fault with one of there 46" screens? Its either the ssl460-3e1b inverter board or the led strips have replaced theIC001 on the inverter to no avail.
TIA Davy.

Mulja tv repair portal · « **on:** October 22, 2015,06:58:16 »

Turnip · « **Reply #1 on:** October 22, 2015,11:49:50 »

Hi Davy,

Wonder if you get an initial flash of voltage on the LED strips ? Suspect inverter would fire up just to check if strips are OK.

Realise that in most cases strip failure gives no initial blink, but wonder why as they need to be fired up to check continuity and S/C leds - Chris.

jordan · « **Reply #2 on:** October 22, 2015,12:41:20 »

Check 5 plug/socket of LED stripes LCD display panel.Supply of a LED strrip is 98V. There are 64 LEDs into 4 groups 16 LEDs connecteded in series. The plus of each of the four groups are connected together to the +98V supply. The negative end each group is fed to LED driver board which monitors the current of each of the four groups.

Mulja tv repair portal · « **Reply #2 on:** October 22, 2015,12:41:20 »

old tvman · « **Reply #3 on:** October 22, 2015,12:50:08 »

Yes I get a short flash with the 90v coming up momenterally then nothing.

Turnip · « **Reply #4 on:** October 22, 2015,12:58:15 »

Hi Davy,

Guess Jordan is right and you have just 256 LEDs to check - Best of luck - Chris.

old tvman · « **Reply #5 on:** October 22, 2015,15:22:18 »

Thanks for the replies,will delve into the led strip and report back.
Davy

Mulja tv repair portal · « **Reply #5 on:** October 22, 2015,15:22:18 »

jordan · « **Reply #6 on:** October 22, 2015,16:25:24 »

Check-one LEDs it is O/C

old tvman · « **Reply #7 on:** October 27, 2015,05:54:43 »

Stripped it down and using a 19v dc supply tested the leds 4 at a time,they all seemed ok with 3 or 4 of them slightly dimmer than the rest.Have ordered an inverter board from China.
Here's hoping Davy.

Southerner1959 · « **Reply #8 on:** November 04, 2015,06:37:41 »

This is what I don't understand . . .

I have a similar fault on an LG with LED Backlights . . .

Everyone is saying it's the LEDs . . . but I don't understand how they can flash on for a moment at switch on and off if they are faulty!

(I would check them, but looks a really difficult job to get the screen apart)

Can you tell me . . . what do you see if you measure resistance across the cables leading to the Backlight?

old tvman · « **Reply #9 on:** November 05, 2015,16:39:44 »

southerner1959, its almost certain to be an open circuit LED on one of the LED strips, its a very delicate job dismantling a 47" screen and great care must be taken with the screen, however if you attempt it its quite simple to locate the faulty strip by applying a 12v supply to the 4 led strip or 15v to the 5 led strip ie 3 volts per led .
Good luck davy

old tvman · « **Reply #10 on:** November 24, 2015,13:11:36 »

Replacement inverter board cured the fault. Phew.

Mulja tv repair portal · « **Reply #10 on:** November 24, 2015,13:11:36 »

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