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Crumbtrail TV Forums: TV Equipment: TV Repair Forum:
Toshiba 40l1333b (SSL400_05DA) - backlight problem

 

 


dfear
New User

Nov 7, 2018, 7:51 PM

Post #1 of 2 (158 views)
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Toshiba 40l1333b (SSL400_05DA) - backlight problem Can't Post

I have a Toshiba 40l1333b with a backlight problem.

Problem:
The backlights don't light up.

Screen: Lta400hm23
LED Driver board: Ssl400 0d5a- Rev 1.0
Back light LED Strip connector board: SSL400_WP01 REV:0.0

Firstly I replaced the driver board, but that didn't fix the problem.

with the replacement driver board connected, I tested the led strips with an LED tester and all the leds light up.

I tested the leds using test points VOUT and IS (which are on the led driver board).

Also i have checked the continuity from the led driver board to the led strips, and continuity is OK.
I think there is a fault with the led driver board. I have attached two photos of the led driver board. The photo with just black test shows what the voltages should be at various points (i found these voltages from a photo I found on a forum). The second photo ( with the green text) show the results of testing the replacement driver board.

---------------------------------------------------------------------------------
Any clues which component on the led driver board in faulty?
----------------------------------------------------------------------------------

Update: I replaced the SN358 op-amp with with a LM358, but it made no difference.

Here is a number of photos with varying test results
-----------------------------------------------------------

correct voltages on SSL400_05DA
http://testing.dfear.co.uk/...2-1.black%20text.png

results of testing original SSL400_05DA (from the tv)
http://testing.dfear.co.uk/...20test%20results.png

results of testing replacement SSL400_05DA
http://testing.dfear.co.uk/...20test%20results.png

results of testing SN358, TR10E and CN001 - original SSL400_05DA
http://testing.dfear.co.uk/...-%20ic%20results.png

results of testing SN358, TR10E and CN001 - replacement SSL400_05DA
http://testing.dfear.co.uk/...-%20ic%20results.png



dfear
New User

Nov 8, 2018, 7:36 PM

Post #2 of 2 (144 views)
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Re: [dfear] Toshiba 40l1333b (SSL400_05DA) - backlight problem [In reply to] Can't Post

I have fixed the backlight broken on this TV.

The problem was the crappy connectors that connect the led strip pairs together.

Solution:
I have soldered solid copper wire jumpers between the pairs of led strips. Only one connection was faulty but I put copper jumper wires between all of the led strip pairs, on both the positive and negative connections.

FYI:
The voltage on the LED tester (after the repair), when putting the probes on the IS and V_OUT test points on SSL400_05DA, was 124V.

FYI:
I used the solid copper wire from 1.0mm2 twin and earth electrical cable to make the jumper links.


https://obrazki.elektroda.pl/...70300_1541702334.jpg



(This post was edited by dfear on Nov 8, 2018, 7:45 PM)

 
 
 


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