Good sir, thank you very much for this video. My LNT-4661 had this exact problem, and I performed your steps identically, and have a working TV again (with the ever so slight dark band). I had purchased an $1800 plasma (decided to buy high end), but can now return it and put my LCD back up, you saved me a lot of money today. Fixed for $75, the cost of a multimeter, soldering iron, and some miscellaneous items.

Excellent video, thanks. This was exactly the fault on my LE40C650, picture and sound came on initially then picture went blank. Managed to work out which backlight tube was causing the overload protection to shutdown the inverters. Slight complication on my TV in that the inverters drive a pair of tubes as one dual output device. Managed to lift the leads on one of the secondary outputs and insert some insulating plastic film and then bypass its primary side so I did not have to remove the entire inverter. Saved me loads on a new TV, missing backlight barely noticeable.

thank you for enlighten and you help me a lot to repair my mom tv and save more money to buy a new tv,thanks a lot

Excellent video! Thanks! I've been trying to diagnose an older 46" samsung LCD that has backlighting coming on on one side only. Do you think this same issue may be causing it? Or would it likely shut the whole set off, like you mention? I have picture and sound, just very dim on left side (backlighting not coming on). thanks!

Awesome details and thanks for that little bypass. I am stuck on one TV right now and was wondering if you knew if this is even an error code or what. I have a Samsung UN60J6200AF and it doesn't turn on AT ALL. I get 6 flashes on the red power LED. The blue light on the LED board remains solid. I also have a solid red led on the mainboard. At first I suspected the power board, but the fuse and capacitors are fine on that. I could not get the LED panel to light up, even disconnecting the mainboard and powering on the system. Before I go any further I just wanted to know if you had any insight on these sets or if you could point me in the right direction.

Fantastic! I have a 4661F, very similar TV, with same issue. I followed your approach, with my rudimentary meter, planning on taking the same approach with a cheap solution w/ a jumper. However, as I was testing, on the 2nd/3rd transformer, the TV started working again. What could I have done that would have 'kick started' this? Some sort of short, or something loose that was re-adjusted?

Great video and great to have somebody on KZfaq that knows what they're doing.

Great video. I;m also looking how to determine which type of jumper to use.

MANY MANY THANKS !!!! This tip fixed the TV I was working on Thanks for creating!!!!

Did you make that stand? If so, Can you share how you made it? That would be VERY nice to have and would make things a lot easier!

Samsung LN 5285F. I wanted to try and test my inverter boards using a voltmeter but you never showed where to ground the voltmeter probe just where to test. I have since ordered and received 3 of 4 inverter boards from you ( LL,RL, and RU ). The LU you didn't have in stock. I replaced the 3 boards but made no difference. The original problem was that the tv would boot up, picture would start then drop out. Audio but no video. Not sure where to go from here.

Followed this to diagnose and repair a Sony Brava KDL 40S4100. It worked just fine. Thanks for the great video and clear instructions. Another TV diverted from the garbage.

Hello, You said the Florescet tube was bad. How did you test that??? Also when you were testing the transforms,Where did you have your negitive lead?? Thank you again for shareing you knowledge... I've got one that has backlighting problems that I'm trying to fix.... messge me back please, when you get a minute..

Common chassis ground, any metal part like the back of the panel or even the ground on the in/out jacks.

Where do you have the multimeter ground lead connected to? Your testing with the positive lead on the test points but I don't see your ground lead connection.

I have an LG 50-GA6400-UG Same scenario; picture goes out but the sound works well. I can see the picture in the background with a flash light . The inverter board was replaced twice and both times failed within a week. Could it be something else that is blowing these boards or did I get bad used boards?

Is the negative lead attached to the frame of the TV?

hi norcal, my 40" samsung has sound and picture, but no backlight. there are no popped/bulging caps on the power supply. after watching this video, i attempted to go through and test the transformers. in the video you have a single test point coming from the two feedback pins. on mine, there is a test point coming off of each one of the 4 pins. so, i put the positive pen on one of the 2 inside testpoints, and the negative pen on the other one of the 2 inside testpoints.(continued)

Hi i have a samsung le40a556p1f when I turn the tv on it works fine for 2 seconds then the back light goes off i have replaced the inverter board but still no change. Any ideas would be appreciated

First, I would like to say all your videos are great. You are one one the smartest technicians I have come across on youtube, thanks for all your hard work. I have a dynex dx-46L150A11 and roughly 6 months ago I replaced the backlight inverter board, cuz after 40-60 secs of powering it on I would loose video but not audio. It worked great for the last 6 months and now I'm having another issue. If I power the set on I get the "please wait" message then it goes black but audio works. I did the famous flashlight test and I can see the video playing. So my question is does this sound like the backlight inverter board again? I did a physical check of all the boards and there is no sign of anything burnt out. It just has me puzzled, cuz last time, before I changed the backlight inverter board the video would last 40-60 secs before going black and now it goes black right after the "Please wait" message. Can you tell me what you think? Thanks in advance

I am sorry but I dont know where you can get new fluorescent tubes also. I would suggest the you find a scrap set with the same size panel and try and replace those tubes. I have had great success with that.

is the dark side a sharp cutoff or is it gradual? If it is gradual then it is most likely the panel, sharp difference between sides could be the tcon.

How many LED strips do you think I should use on a 42" to stop the risk of shadowing. I can power the LED's through a plug and socket arrangement with an external supply. So numbers is not an issue for the internal power supply of the TV.

Great video. I have a Samsung 46" LCD model LN-S45920. The back light is on, as well as the sound...but no picture. Just a warm, glowing black screen. Do you have any idea what might be wrong? Perhaps the T-con card? Thanks for your support. Dan Tietjen

Based on the ringing test of the transformer and the feedback voltage thats all it could be. The negative lead for all of the voltage measurements was on chassis ground.

Just found your channel , thanks a lot ! I wish tho I found this a year ago when I had a set that was doing this (im no expert like yourself) ended up ripping all the bulbs out and replacing them with 600 leds on strips and adding a 12v 2a psu and while it worked , this would have been a lot quicker as it was doing exactly the same thing but I could not for the life of me figure out how to bypass a bulb like that !

Yes I have done that in some sets, this customer just wanted a quick fix and didnt want to spend any money on this set. It was given to them.

I agree most likely main board. Red LED should blink while set is starting but then go out after that.

You can measuring by ring tester if transformers is good or bad for the simple moves

how am i supposed to remove my inverter? it looks like yours but is feels like its on to something when i unscrewed it and tried pulling it out, I'm guessing that is the backlight bulbs? So I'm sorta stuck here because I don't want to force it so am i supposed to slide it off the black plastic part?

Where do you put negative lead when checking ac.voltage on transformers

Hi there, I have a Samsung LA40R71B and my tv has the same problem as shown in the video. But on seeing the inverter board, my connections are different and the 1st and 4th pins of the transformer seem to be shorted and the 2nd and 3rd pins (which are feedback in the tv shown in video) are shorted and go to the diode via a resister. Please help me out to find the defective tube. Thanks

Hi, My Proscan 42LA45H has sound but no picture or backlights. I am trying to test the CMO inverter boards 4H.V2308.021 & 031/D2, but the test points look very different to those shown in this video, so I would appreciate some help on testing these boards, thanks a bunch.

can i use this troubleshout method on other inverters too? or only for this inverter?

Would this test of backlight work on my Samsung UN55ES6150 Smart TV ?

May have some smaller bad caps on main board as well

How do you access that menu i know its an old posting !

If you were trying it time after time the weak tube may have heated up enough to fire. Try it again when its ice cold and see if it gos out again.

Great video thanks. My problem is a little different. TV is a Samsung LCD LNS4041DX/XAA. When I press the power button, the TV chimes on/off but red LED flashes 4 times and I get no picture OR sound, just black screen. No backlights coming on either and the caps on Power supply board are fine. Which board should I replace? I have some technical knowledge so please help!

I m really sorry I couldn't understand the transformer part what did u do how its work, where did u put the other pin of your voltmeter pleas clearify norcal715

usually the backlight tubes run from right to left so if one were out it would affect a horizontal band. Dim on one side could a lcd panel failure. Look closely and see if you see shadows when there is moving video. I have had many LCD failures with dim picture on one side.

Steve, Would be educational to see how to "ring" a transformer like you mention here. Thanks for including us in your "classroom"! Cheers!

I was thinking of 1cm (10mm) gap between strips. I am going to buy them on a roll. I have found high bright white ones. Would they be ok. Many thanks for taking the time and trouble to help me. It is much appreciated.

I am curious about a flickering light issue. The tv works fine, expect for the blinking. Whatever is on, including all inputs, just blinks. I have read an easy fix for similar models that just has you cutting a jumper (jp852/jp854). Does this fix work on the LNT 4066 models? If so, which jumper would I be cutting? Thanks!

Nicely done video, thanks for sharing!

I love these videos. GREAT JOB sharing with us.

where do you connect the other lead of the meter? Only the red lead is shown in the video.

I don't have the little silver dots to test this tube resistance as you did. By the way, I have a samsung ln-s4051d. This circuit board on mine is a HI40024WI-B and the slave side -H

How do I determine the right gauge/type of jumper to use?

Good morning, I'm in need of advice, my tv has white dots all over, any idea what is wrong? Sound and picture Ok but it looks like stars at night, please advise or if you have a video on 5his repair can you refer it to me, thanks a lot.

I have a Samsung LNT4669FX/XAA with a dark screen on half of the screen with a little blurring in the dark side of screen! I was given an opinion that it might be the T-con board! What do you think my problem is? Thanx!!!

Thankyou, for the advice and posting and sharing your knowledge .. wasn't sure....

Very helpful.Thanks!!!

Thank You...Excellent video, very helpful.

Hi and thank you for this informative video. I was able to fix the backlight problem on the Samsung 4061F in part to this instructive video! Much appreciated!

hi thanks for reply. i can not see the video of the sanyo how can i get that up. im newish on here. thanks

Dear I have a panasonic tv model TH -50ph30w. Power light 13 times blinking. Where is the problem? Thanks

Thank you I am guessing I have a similar issue with a Sony Bravia LCD Kdl 32v40300 is the process the same ?my inverter board id different.Thanks

Hi again, just would like to say if you keep cracked panels you could use a spare working CCFL from them to replace bad ones and then there would not be any darker line on the screen. Takes more time but looks nice.There is many SONY mostly 40inch LCD TVs that I have fixed that way. Regards

hi I have a veon 50inch model:VN50D3LED. my back lights have gone .if done flashlight test image and sound are their but very dark do use have the part for this or what is the most cost effective way to fix thanks

Finally, one good video. Thank you so much!

thank you for sharing your experience with us!, great explanation, excellent

What does esr temperature mean

Excellent Video. I did wonder why the tube was not replaced. Is it because it is not possible or incredibly difficult to replace?

Hi Norcal75, greats videos, thanks for share. I'd like to ask you, where do you get transformer for inverters circuits, I'm looking for a transformer from a Inverter card of Samsung LN52A550 TV, card 01450A, LL, t's the T113 tag on PCB and the number on the transformer is 2034C B 8091, could you please help me to get this trasnformer?,i'm not sure about this transfomer is god or not, it's the transformer how give current to the other tranformer, it's the first T and is not connected to any CCFL.

This is awesome great job of and very informative. Please keep up the great work!!! AWESOME GUY!!

Hi Does this testing procedure hold true for LED tv's as well ? Thanks for the video , wish your shop was close by me :-) The two guys Samsung referred me to carried guns lol....Wanted $150 to drive out to look at the set and the second came out for $100 , didn't open the set up and said it was the Main board and wasn't worth fixing (2 1/2 years old) but offered to buy it from me . A $1300 tv not worth repairing ???

Hi, Norcal. I have a 32" Toshiba tv mdl #32av500u. It turns on, the screen lights up but there is no picture and no sound. Can you assist me please? Thanks.

look around the inverter transformers for little blue capacitors, look at the color very carefully and see if if any of them are discolored. I have had a few leaky capacitors and they discolor when they get hot. A good shop should not charge more than $125-$150 on a 32 inch for this repair.

Thank you! Thank you! Thank you! This was exactly the problem with my TV. (Well the caps had also gone bad... )

Hi, I don´t have any voltage on connector betwen power suply and backligth panel. Capacitors are OK, where can i search for damage? Thanks

I have an LN52C530 and my entire backlight has just gone dim (or possibly out), but the TV doesn't shut itself off like the one in this video. That leads me to believes it's not one of the transformers or a tube... correct me if I'm wrong. Any idea what it might be?

Samsung LCD # LN40c630k1fxza, tv works fine for 2-3 weeks, then black screen w/ sound. I did the flashlight test you posted and TV is on , but back light is out. I can unplug TV and turn it on a week later and it is fine. I want to purchase correct part, but not sure as it works intermittently. Please assist with your thoughts, thank you.

I have a Sony kdl 40s3000 that has a dim picture even though I have maximize the settings. Is this a backlight issue or something else? Thanks

Hi- great videos!!! I have a RCA model RLC3708A 37" that is doing the shutdown after powering up the backlight inverter.. the inverter transformers have 5 leads one end & two on the other...The ac voltage at the test points goes to 26 volts before the system shuts off..Can you give me a clue on what to do next. ps. all the backlights turn on momentarily and the red-off , light does not flash..Thanks...

Is it possible to convert these Samsung TVs to LED back light? If so what is the best source for the kit?

hi there m8. i have a samsung le40n87bd lcd tv the fault is i have jumpey lines on the left hand side on the screen after 30mins or so it goes of or if i hit the tv. what board is it needs fixing or replaced. i do not know how to upload a picture so you can see what i mean. thanks

I have panasonic viera 32 inch lcd tv bearing mode no Th-l32c8dx.the other day while removing from wall mounting ,it slipped from hand and the lcd panel hit the knee and after plug in the panel showed broken glass image in bottom,an area of 6 sq cm.then when i start cable the same image with vertical lines start appearing with the program sound coming good .pls advise its disposal asap.thanks

I wounder how difficult it would be to replace the CCFL it's self???

Hi I got a 42inch Sanyo TV model no.42840 the issue with it is the green led keep blinking no picture or sound help please thanks

Where is your meter's black probe connected?

Please let me know that camera was recorded on video. make and model of the camera ....

In a response and the iPad app cuts off and sends it. I replaced power supply, no change. All boards appear good with no burns, capacitor bulges or broken solder joints. No clocking/power on/off issues. Sound is good, no backlight though lcd appears functional with flashlight upon close inspection. Used multimeter to rookie test inverter boards. There are 4 leads on the inboard side, 2 on thee outboard side. I tested the outboard side and all report about 343ohms of resistance save one that rea

Very nice video it will help my save many TVs.

My TV is Samsung ltn4071fx, has and 5 years, 1) when I turn the tv out a red stripe on the left side of the screen when the TV is turned on this time slash disappears. 2) when the TV is turned on about 15 minutes in the red band image is small or hairline but this is displayed in the picture.

LOL wow this was recorded 8 years ago. This tv was probably modern when you made this video.

Samsung un40f5500afxza works fine except for a dim 6" or so horizontal dim band on lower section of screen, just was given tv and want to save it if possible

Just from your description sounds like you may have a bad LCD panel, look at my "Sanyo LCD" video and try that

I have a sharp LC TV model number LC 50 ub30u serial number 505 BO2 15853 the TV has power it goes on but there's no light I also have sound could you please show me a video on how to fix it

great video. I love your videos, you show some hackery to just make it work. Why not replace the tube? Another thing I wanted to ask you have you tried using other parts from other makes of tv's just to get them running. The reason I ask I have 1 spectra 32 inch and a samsung 39 inch they both use au t-cons the spectra has a bad screen and the samsung has a bad main and t-con with not being able to find a replacement main for the samsung. Out of pure desperation I hooked the main and t-con out of the spectra to the samsung to my surprise tv started right up the spectra is led so for the back light I think I will use the led out of the spectra in the samsung right now I have 2 plugs one powering the backlight-power supply in the samsung and one driving the screen-main-t-con. Even if I could find a main I am not sure the tv would be worth repairing the cost of them are so low at this point.

I have a Samsung LNT 4671FX/XAA. It has sound but it also has some vertical and horizontal lines which vary in colors. ranging from red, blue, orange, white and black. Any idea what is wrong and also. Are you located in Northern California, is that is the case, how can I contact you?? Thanks in advance

I'm currently working on this same problem with a different samsung lcd I'm not sure where my measure points are could you help me? If I sent a pic of the board Thanks

hi I have a Samsung tv LN-T4066 and the audio do nor work properly sometimes , can you advise me what to do? do I need a new main board? also can you explain to get the main menu to reset my tv settings ?

Good video, I have a Samsung T220HD. When I turn it on the picture comes up for about 2 seconds then goes black but the sound and power light stay on, this repeats exactly after restarting. The image is on the LCD because I can see it with a torch (flashlight) - is this likely an inverter problem?

Hi, I have a Insignia 42 LCD model: NS-42L55A11,have a sound but no picture can you help me pls thank you

Sounds like you may have a bad LCD panel itself especially is one side is good and the other side is bad. Most likely not the main board or even the tcon.

LCD TV Samsung LN32B550K1MXZD has no VIDEO and no SOUND and the RED LED is blinking. The CCFL backlight lamps do NOT turn on. I tried to fix the IP (power supply/inverter) board, but I could not find any problems.. All voltages specified on Service Manual are OK including the 30-pins connector to the MAIN BOARD. When I disconnect the MAIN BOARD from IP the CCFL lamps turns on. When I connect ONLY THE MAIN BOARD (without T-CON) the lamps turn off). I suspect the MAIN BOARD. What do you think ?

Hi. Hope you can give me some advice. Got a Sharp LC-40SH340K. It stays in standby, with blinking SB LED every 1 second. Check power supply outputs, and they are correct. Also tried an additional power supply that is know to be working. No Luck. Checked power going to inverter and it is correct. not sure what i can test. There is no error line that is sent back to the power supply. However the power supply relay dosent click either. The Panel is - Samsung LTA400HM07, TCON is LJ96-05827A inverter is SSI400_12A01. Power supply is the crappy - Vestel 17PW82-2 V1 090511 (one bought just to test) Any other ideas what to check ? As I cant get any function from it then Im at a loss. is there a way to trigger the BL on/off line to test the inverter and leds. I believe the TCON is mounted along the top edge of the panel, so not easily accessible !! Could it be the AV board ? Look forward to your reply. Seems a shame to bin it. Cheers, Adam

I checked 3a pico fuse on VO ctrl board. and I'm getting 10v

I have an asus PB278Q 27 inch monitor with a totally with screen display and no video reproduction? Cables are connected nice and tight. Any help?