When first plugged in, press power button... LG logo appears for less than a second, then screen goes black. The red light at the power button comes on, turns off, then blinks twice. Watching from the back with the cover off, the backlight flashes on and then off. A red light on the main board under the heat sink turns on and then off, as does the red optical port light. Subsequent attempts at powering on the TV without unplugging it first will show the same except the backlight never comes on, and the logo doesn't appear. Have replaced power board. Cleaned and reseated connections. Tried flashlight test, could not see any picture. Tried baking main board for 10 minutes at 385F. No burns or obvious issues visually apparent in TCON or main board. Cables all seem intact. What is the likely culprit?
Have you checked your power supply voltages?...if so what are they?
Testimonial: "Have not checked them TBH. Figured since the problem persisted through replacing the power board that it would be elsewhere in the TV?"
Have not checked them TBH. Figured since the problem persisted through replacing the power board that it would be elsewhere in the TV?
Main reason to check them is to see if you have backlight issues and see if the backlights are shutting down the power supply
have similar issue but haven't changed power board. (hard to find). my 13.2v supplies measure 10.2v I get the quick LG flash and red light on main board blinks and stops. unplugged cable from PS to Main same voltage. unplugged LED cable same voltage
Did you solve the problem? I'm having the same problem.
What is the part number of your power board Jim Oliver?
anyone figure out the issue? im having the same issue but i unplugged everything but the power supply and main board and it is still doing it. And since some of you replaced the power supply with no luck than it sounds like it has to be the main board. Has anyone replaced the board?
I have exactly the same issue. I changed the power board and the main board. I get a flash with the lg logo then nothing. Is there any way to check the led lights without tearing apart the screen?
No. Don't tear apart the screen or you will break it. Can be taken apart and fixed with a soldiering iron
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Led back lights joiners between the led strips need jumpers soldered on
The LG model sets with UH5500 after the panel size do not have jumper between the strips, they have local dimming, each strip has it's own power supply. See answer below on how to repair the TV
Best thing to do first is turn on tv. Press menu button then look at the screen carefully with torch or sun light and you should be able to see menu very faint. If you can then it is the back lights.
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SOURCE: Power button Flashes
Bad Convergence circuit , replace 2 STK392-110 & fuse will take care the problem
SOURCE: I turn the power buttin on....after about five
When was the projection lamp last change?If the tv,projection lamp inside the tv at last change was 1/ 1/2 or 2 years ago,and the tv is on,an in use at lest 4 or 5 hours day.The projection lamp life,it over should be change the projection lamp.Now tv turn on LED light "LAMP" indication light up or flashes?Yes,the projection is dead,hear alot of clicking too?The Ballast board it also dead,should be change too.The Ballast board,this board job,it help to ignite the projection lamp.
SOURCE: I have a TDA-03211C Polaroid TV. It powers on,
The power supply board have more than just two capacitors problems,could be anythings else like a diode,transistor or those transformers on the power suuply board,u have no trouble shooting skills or tv repair experience,will never figure it out.Tries websites like Shopjimmy.con,Ebay.com to buy a whole refurbish power suply board for the replacement.
SOURCE: LG 55lh40 tv will not turn on. I REPLACED THE
Only a probe with a voltage trace can figure to the possible SHORT in the circuit board. You need to look for possible signs of heating which can be an indicator to a short . Also check for the secondary +B to the circuit, check the path that leads to the drive and see if there is high potential drop, if so check the drop to get an idea of the short. The list of probabilities can be more and so ONLY a good voltage check can pinpoint the case. Take consensus but do not replace board at high cost with just assumptions.
SOURCE: My LG 37LG50 TV wont turn on ?
Are you certain the replacement power supply is good? A defective main board or power supply can cause this problem.
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I have the same issue. I changed the power board and the main board. Is there a way to check the backlights without tearing apart the screen?
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