Toshiba 58L1350UC LED Flicker

[Choons2091]

Hi Folks,
First day and first post on Bad Caps so I apologize if I am missing some info or have formatting issues.

I picked up this Toshiba Tv for free off kijiji and am trying to get it working again. When plugged in the On indicator goes green then there is a 1 second flicker of the LED's. I found a couple bad LED's on the bottom row and replaced them individually however the issue persists. When using diode mode all the led's faintly turn on but when my leads are reversed THE ONES THAT HAVE BEEN REPLACED SHOW OL while old ones give .75

These are the led's I ordered. The picture attached is a original led.
https://www.digikey.ca/en/products/d...5AIoHAEIAugL5A


My question is what should the correct led's be and is this what is causing the flicker?


Model: 58L1350UC
Fabricated: November 2013
SN: D47267T18198C1
AC in: 120V 60Hz

5V 3.3V and 12V all seem ok.
For the led
LB1+ LB2+ LB3+ LB4+ LB5+. all 120V
LB1- 0V. the rest 20V

Thanks in advance for any help and input.

[Diah]

Re: Toshiba 58L1350UC LED Flicker

When using diode mode all the led's faintly turn on but when my leads are reversed THE ONES THAT HAVE BEEN REPLACED SHOW OL while old ones give .75

the one you replaced could be normal LED with out ziner diode ( not for TV BL ) or its had but the ziner diode Open ( defect )

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

the one you replaced could be normal LED with out ziner diode ( not for TV BL ) or its had but the ziner diode Open ( defect )

Hello! All new led's are like that so I must have bought the wrong ones. Thanks I didnt know they had a zener diode in them. Is there a way for me to bypass the new led's to test if that is whats causing the back lights to flicker for a second then turn off?

Also what does "TV BL" mean?

[Diah]

Re: Toshiba 58L1350UC LED Flicker

Hello! All new led's are like that so I must have bought the wrong ones. Thanks I didnt know they had a zener diode in them. Is there a way for me to bypass the new led's to test if that is whats causing the back lights to flicker for a second then turn off?

Also what does "TV BL" mean?

NO. dont try any things to damage the TV .. put it on side and buy correct LEDs

BL -- backlight

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

Alrighty thanks for the tip. One more thing, how do you know what the correct led is to order? I now know to get it with a diode and using a power supply i determined it is in the 6V range but how about watts?

[Diah]

Re: Toshiba 58L1350UC LED Flicker

Alrighty thanks for the tip. One more thing, how do you know what the correct led is to order? I now know to get it with a diode and using a power supply i determined it is in the 6V range but how about watts?

how do you know its 6V LED?
on the strings of led there are label show us here,,, and show us one of the old / original ( defect) one which you need to measure its size in mm (Millimeter) so you know the type / size) for example LED Type 3030 its 30mm x 30mm , and you need to see the downside of the LED ( the chassis figure ) to pass on yours strings chassis.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

how do you know its 6V LED?
on the strings of led there are label show us here,,, and show us one of the old / original ( defect) one which you need to measure its size in mm (Millimeter) so you know the type / size) for example LED Type 3030 its 30mm x 30mm , and you need to see the downside of the LED ( the chassis figure ) to pass on yours strings chassis.

Uploaded request! I used a power source to test a good led and achieved a good brightness at 6V. I know this is not a very accurate way to do it.... Open to suggestions.
Size is .118 X .118"" or 3mm X 3mm
Height: 0.020"" (0.52mm)

[Diah]

Re: Toshiba 58L1350UC LED Flicker

look if you have another label on the string. but i can say they are 3030 6V 1W

normally if you have found as you wrote couples failed led on one strings row. mean you have open soldering joints at the strings socket need to rework them

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

look if you have another label on the string. but i can say they are 3030 6V 1W

normally if you have found as you wrote couples failed led on one strings row. mean you have open soldering joints at the strings socket need to rework them

I attached the only other label which was on the back of the string. Sounds good Diah i will rework them. What makes you think they are 1 watt instead of 2?

[Wilderone]

Re: Toshiba 58L1350UC LED Flicker

Check the polarity, some are big pad negative & some little pad are negative.

[Diah]

Re: Toshiba 58L1350UC LED Flicker

What makes you think they are 1 watt instead of 2?

.V & .W are always Values of the maximum operation, 1W are enough for TV BL

from the label it say the white Temperature 3600K , so you need to be sure on one things.. test one original LED with very low currents to see if there 1 cell or double cell lighting on ( lighting point ), some are come with double LED all in one.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

Check the polarity, some are big pad negative & some little pad are negative.

Thanks for the comment. So I just checked and the led only turns on when positive is on the little pad and negative on the large

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

.V & .W are always Values of the maximum operation, 1W are enough for TV BL

from the label it say the white Temperature 3600K , so you need to be sure on one things.. test one original LED with very low currents to see if there 1 cell or double cell lighting on ( lighting point ), some are come with double LED all in one.

OK so i just checked and it is very difficult to make out. It's either one large square led but I think its 2 small rectangles. On my original post I attached a picture of the led under a microscope.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

OK so i just checked and it is very difficult to make out. It's either one large square led but I think its 2 small rectangles. On my original post I attached a picture of the led under a microscope.

I now have welders flash but am confident it is 2 leds lol

[budm]

Re: Toshiba 58L1350UC LED Flicker

OK so i just checked and it is very difficult to make out. It's either one large square led but I think its 2 small rectangles. On my original post I attached a picture of the led under a microscope.

https://www.badcaps.net/forum/attach...8&d=1612741555
The two squares you see in the picture of your LED are the LED dies and they are connected in series with bonding wires as you can see in your picture.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

https://www.badcaps.net/forum/attach...8&d=1612741555
The two squares you see in the picture of your LED are the LED dies and they are connected in series with bonding wires as you can see in your picture.

Thanks Budm. I read your troubleshooting guide - very informative! On my LED strips (23 6V leds per strip) I have 120V on positive and 20 volts on negative but they dont turn on. Any ideas?

[dick_barton]

Re: Toshiba 58L1350UC LED Flicker

23 leds at 6V = 138V so it looks as though you still have a led(s) fault or a poor connection between strips.
What is the voltage as you power up the set at the led connector. It may peak higher and then drop quickly to 120V

[neilc6]

Re: Toshiba 58L1350UC LED Flicker

This model (and Toshibas in general) is a nightmare since bad LEDs can damage the controller IC on the power supply and vice versa. I ended up buying a new set of strips and the bad controller damaged one of my new strips so had to put an old one strip back in with a new power supply. Wouldn't touch this model again.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

This model (and Toshibas in general) is a nightmare since bad LEDs can damage the controller IC on the power supply and vice versa. I ended up buying a new set of strips and the bad controller damaged one of my new strips so had to put an old one strip back in with a new power supply. Wouldn't touch this model again.

Hi Neilc6 I was actually reading your post on the led strips/ic issue and I put the ic chip in my shopping cart haha.

[Choons2091]

Re: Toshiba 58L1350UC LED Flicker

23 leds at 6V = 138V so it looks as though you still have a led(s) fault or a poor connection between strips.
What is the voltage as you power up the set at the led connector. It may peak higher and then drop quickly to 120V

Just checked and it was pretty stable. Maybe the brightness was down in the settings. I'll replace the led when it comes in and keep everyone updated. Any website recommendations to order individual leds?