Re: Toshiba 50l1350u low power to LED

Hello Guys

After a couple weeks of wait, and having enough time to sit and do it, finally i got the resistors and the mosfets and replaced them. Now i have no power
I went ahead and replaced both mosfets, even though one was okay. So i'm not sure if by removing the one good mosfet(asuming the ones i got are not good replacement) would cause me the no start.
i replaced the P0920ATF with IRF630.

Anyways i took the readings out of this plug

and i have:
0v on 15
...

Re: Toshiba 50l1350u low power to LED

Thanks for the link Dick, that will be the option to go if the Ic is damaged hope not haha. I found this
[URL="http://www.st.com/content/ccc/resource/technical/document/datasheet/bf/f6/23/6a/d8/7f/4a/e0/CD00000701.pdf/files/CD00000701.pdf/jcr:content/translations/en.CD00000701.pdf"]http://www.st.com/content/ccc/resource/technical/document/datasheet/bf/f6/23/6a/d8/7f/4a/e0/CD00000701.pdf/files/CD00000701.pdf/jcr:content/translations/en.CD00000701.pdf[/URL] to replace the [URL="http://products.niko-sem.com/images/product/1387166258769732102.pdf"]http://products.niko-sem.com/images/product/1387166258769732102.pdf[/URL]...

Re: Toshiba 50l1350u low power to LED



The mosfet is BAD So from here What to do? should i just get a replacement board or will it be worth it to try and replace the mosfet and the resistors and see if the IC is working? what would you guys do?...

Re: Toshiba 50l1350u low power to LED


i missed this post ...

Re: Toshiba 50l1350u low power to LED



haha Well im sending you the best pictures my crappy iphone can take. Luck would had it that my motorola with superb camera died on me a few days ago. Anyhow we are thinking alike while you where telling me this i was tracing all the burnt components and came to a suspect : Field Effect Transistor. P0920ATF


I traced the circuit source in red, where they split on the 2 channels and marked where the burnt resistors are with the pink bus/boxes.
i need to test that P0920ATF
...

Re: Toshiba 50l1350u low power to LED

Is faster if i just give you the numbers
Customer Barcode Labelthe large sticker)
03-PK101W0100I-VDAFL-DO9-0302-100

Smaller sticker :
B178-B01 D09 REV.C
2D 00015 54611 01815
yes there must be something burnt. There are 2 circuits that drive the the 2 different led channels. The mirror circuit has its 3 resistors good. So its something on that specific circuit.


I read about 12k ohms on the rl 22,23,24 resistors 16k on the rl 21 (nearest to the chip) 15.6k on rl 19...

Re: Toshiba 50l1350u low power to LED

Thanks again for the help
this is the image i made up. Tried different ways to capture the buses and the failures i found.


Im not an expert at electronics but they seem bad to me? have to remove them to test them right?

Re: Toshiba 50l1350u low power to LED

spent a few minutes trying to find the datasheet of that chip and it proved to be a tough cookie xD haha anyhow ill try to check the mosfets but im trying to post a picture with s(what i believe) are some blown resistors. While checking on that Driver i kinda found 2 pins that the solder looked different than the rest. And sure enough there seem to have been something wrong on these channels. But since the camera i have is so terrible its taking me some time to put it all together xD

Re: Toshiba 50l1350u low power to LED



Thanks for the reply Dick, when i took it apart i saw 2 led channels(hence only have 2 L+) there are 12 strips(6 rows 2 strips per), each strip has 5 led so its 60 leds total. they did power on when i used a 22 volt dc power supply on each strip. I hope these are the chips you need to see?

Re: Toshiba 50l1350u low power to LED



Okay did this and still got the voltage rise up to 72 volts. It really doesnt rise that fast as i could read 35 volts 50 volts and then 72 volts. My meter is very cheap so no max min function....

Re: Toshiba 50l1350u low power to LED

hello Budm Thanks for your reply, I read .3 volts with the set off on both L+
and they jump to a stable 72 volts. I see no voltage spike while turning it on(beside it rising to 72v) I tried verifying the voltage out of the transformer but my voltmeter could not find the reading not even on the 1kv setting. I have no idea about that though. Its evident some voltage is coming out of it since i can get the 72 volts. Thanks again and sorry for the late reply

Hello guys. My toshiba 50l1350u tv has a problem. I can shine a flashlight at it and get to see the display. So i thought i had dead LED's and took it apart and realized the LED's are all functional(powered each strip(12). So it became evident i had no power to drive them. Should have checked that first anyways i pluged all back and read 73 volts on the Led outputs. it has 6 strips of leds divided in 2. Both outputs read 73 volts. With leds plugged in. At night i turned the tv and was able to operate it(just the menu) with the remote without the need of a flashlight, because the leds...

Re: New Members - please post your introductions here

Well Hello! My name is Gabriel you all can call me Gundulf.
I am from Puerto Rico USA. I studied computers and electronics( a while ago haha!)
I am a handyman for a living. I am very DIY oriented to the point i've learned from cooking, mechanic, 3d printing, sewing, gardening and so many other stuff by the wonders of the internet and gracious teachers all over the world. While i can mostly figure out mechanical stuff, electronics are always a lil tad more harder on me. So ill be counting on you'all Thanks and any...