65 inch ONN Roku TV has no backlight just a Black screen. 

I highly appreciate your honesty by showing the replay. Cool video.

LOL, Good on you for showing how you messed up that fet. We all do it, few have the guts to admit it on video. Respect for that. Thank you for posting it, I think I might have the same issue on the dumpster find I'm trying to fix.

I find tvs and grab them and try to fix them and your videos have been very helpful so thank you!

Love it, total honesty: You show the mistakes as well 👍.

Excellent video. I'm learning a lot from your logical approach in troubleshooting. Thanks for uploading it. I'm intrigued by that LED tester, as I've never seen one before. I'm guessing it is a constant current source that stays within the limit of the LEDs to show if there is an open or a short. My 50" ONN "dumb" TV quit working one day after 2 years of great service, but when I shined a light at the screen I didn't see any ghosts, so I didn't think it was a backlight issue. I watched your video about the NVRAM chip replacement and was going to try replacing that IC, but my wife was wanting to watch TV and I was taking too long, so I bought a replacement Samsung "smart" TV, which I can't stand compared to the ONN. (Smart TV's in general, I don't care for). Perhaps one day I'll pull the ONN out of storage and have a 2nd try at fixing it.

Nice video and i noticed when checking the mosfet underneath the power board that coating looked like some kind of spill but great analysis

Very nice troubleshooting

I hate it when I hear that snap sound, it means I messed up. Thanks BD!

Great video on this issue

Best video out there what are these boards called is there a serial # I can find on my board so I can order same board I have 75” Onn Roku tv

Thx for all your video. They inspired me to open up my TCL 50S45 to replace the HBH-L2 2228 21 led single strip. But I can’t seem to find it anywhere. Any suggestions?

Great, Keep going 👍

Excellent work. I do wonder what conformal coat the manufacturer uses. I've used xylene for most conformal coats I've had removed, which helped a lot since I can probe much easier without deforming probes or damaging solder joints and/or boards. EDIT: The usual manufacturers make offer their own "formulations" with different applicator styles (Chemtronics, TechSpray, MG Chemicals, MicroCare, etc.).

Where do I get a onn power supply board from

I have a Hisense with the same problem as yours do you think it could be the same problem?

How do I fix it if I can see the picture with a flashlight

Thanks for showing what the ultimate point of failure was, I kinda suspected it would be, I had something occur like this before with higher than normal voltages & that was the fault. I like the new scope ... how do you like it?? Seems to be reasonably priced on Amazon 🤔.

I'm good at basic problems , but can't work at your level. Where did you get your training ?

Can you tell us where you order board for ONN?

I like you you will teach me more about Electronic

did I miss what the actual issue was? I know you said you accidentally popped that chip, but was that transistor the real problem? I have an Onn 70" Roku TV with no backlights, just the initial flicker, and it is "on" when you use a flashlight against the screen. Doing quick observation, the 10uf 450volt capacitor at the backlight section is swollen, so I'm going to replace it first, as I can only find used power boards on ebay from China at the moment.

Love your videos, very detailed. I have a TCL 75S421 with dead LEDs but can see the image with a flashlight. The power board is giving me .66v to the first two red LED wires but the second two are 0v. Can I test the LED strips with my DC Power Supply Variable?

I changed my backlights on a 65” TCL and when I got it back together there were vertical lines going down the right side of the screen. Can you tell me what could that could be. I checked the connections to the main board and T-con board and all are connected correctly.

How was you able to disassemble this tv that is the problem I'm running into

But it had to have had a different problem for you to begin working on it to begin with. You wouldn’t have been working on the tv and breaking it through a mistake in the first place if there wasn’t a different issue?

I replaced mine but the remote isn’t working at all or any remotes i buy I replaced the ir sensor but still nothing any ideas

Im dealing with this right now, i called a tv repair man they wanted to charge me $350 , i was like i might as well buy a new one lol…, but now that i see the problem i rather do it myself! Do you happen to have the part #? Or the a good link to buy the board ??

How do you take it apart

Bro the oscilloscope is ok to probe pwm dc volts at the secondary circuit ? Because there are high volts !

Can you tell me the link to buy that pwm controller ic ocp 8129b? Thanks

I have the same tv mine was working just fine all day yesterday till about 730 I went to the kitchen fast to get a drink came back and it still had sound but no picture the same thing happened to us a year ago with a tlc roku tv is there a tv that's best to get

Hey! Love the video! I have a question that I need some help with. My tv has no backlight but ghosting, and some leds are burned. The voltage on the led supply is not constant and it shows pretty much 18-22 volts. I am thinking of replacing the led strip but I am worried that the next one will get fried too. Any suggestions or video recommendations on your channel?

Why not replace the part they are available?

Please my brother part me in the right direction of where did you get the tester from that you're using

Hey man is there a way to get in contact with you so I can send you a couple pictures and a video or two if needed about a 2012 model samsung 3d TV that's doing some wierd discoloration at certain times based on what's displayed I could elaborate more here if need be but figured I'd ask and we could email about it or something rather than through the comment section

Which board did you change

Will you get voltage to the LEDs without any other boards plugged in, just the power supply?

That board looks like it was built to a price. Jesus

Need a place to perches tv parts???????

Where are you locateddd omg I need your help

Hey bigdog, I have a quick question I usually test the strips with a led tester as well while they are still plugged into the psu. Is this a problem? I did this on a tv I replaced all the strips on and it seems to be working great. -Thanks

Bro I have the same exact tv. 65 onn roku tv. My wife hit the home button on the remote and next thing you know, it cut off. The redlight is blinking on and off. Black screen. No dimmed image. I can unplug it and plug it back and the red light comes on automatically and continue to blink. Is this what happen to yours? Is this a black light problem im having?

Subscribed

thanks!!

👏👏👏👏👏🇧🇷

Hello, I have a magnavox TV, 50me313 with a suspect bad control board. Will any board marked BA31T0G0 201 3 work in it, or do I have to get a particular eeprom for it? I found a cheap board on ebay, but it's marked as a BA31T0G0 201 2. Will that work? Main symptom is that when plugged in, it makes a chirping sound. When I unplug the ribbon cable from the psu to the board, it stops. I ohmed out "a bunch" of surface mount caps and most of them showed continuity. More than I would want to replace.

Shitty cheap scopes like that definitely have a place because the ground is floating

I heard a soft buzzing sound when I powered on t.v. a month ago. Powered on the t.v. today, and the screen is black. I used my flashlight, and sure enough, there is a picture🤦🏽‍♀️70in onn t.v.