My lg 50uh5530 wont power up. Red light flashes three times.

My lg 50uh5530 wont power up. Red light flashes three times.

My lg 50uh5530 wont come on. No sound, no picture, and the red light blinks three times. Read many Q and A's to discover that this problem can be multiple components from the power supply board to the main board and even the led strips in some cases. I've tried unplugging the unit for 24hrs twice with no luck. I have removed the back cover to visually inspect for damaged capacitors or loose connections and found nothing. There is a faint ticking sound coming from the bottom corner of the power supply board near the capacitors. I also checked the 12 power pins with my meter and I do have a 3.5v standby reading but instead of getting 13.2v for the middle pins I get 6.5 to 7.0v. Looking for further advice to make sure I dont waste money. I'm prepared to replace the caps, the entire power supply board, main board, or any other component to fix the issue. Just dont want to buy an exspensive part like others have done when it may be something simple

Asked by: Guest | Views: 146

Total answers/comments: 6

Comments display order:

bert [Entry]

"@scottcountyhero

post some images of your boards. Use this guide Adding images to an existing question for that. It will allow us to see what you see. Mark where you already checked the voltages. I am not a friend of just going to repalce components unless I know those ned to be replaced. Of course, this is not to say that it will not work, just not my preferred method. I would suggest you measure your power board outputs according to what the outputs are supposed to be. That will give you an indication that yuor power board either works or does not. Remember that certain voltages on your power board will change with input from the main board. Essentially it is the main board that controls teh power board. Again that is not to say that a new power board will not fix this but then again, who knows. The same for your main board and your T-con board.

Update (09/10/2018)

Here is the flowchart for your model.

You do have the 3.5V on standby. Check fuse F2 for continuity and you do see the voltages to the right of the transformer. you couild measure to see if those are existant on the bottom of the board. The part where the clicking comes from, appears to contain at least one diode as well as a power transistor. You could check on those parts. For now, if everything checks out and your board does not have the 13.2Voltage that would mean that this is a bad power board. (beyond bad capacitors)"

bert [Entry]

"Fxed my LG 50uh5530!

It won’t turn on. Blinking LG logo for 0.5 second and goes black screen. The red lamp on the power button blinked 3 times after that.

In my case solution was to replace backlight led strips.

Ordered from https://www.shopjimmy.com

Look this video how to replace: https://www.youtube.com/watch?v=Un80z_fJ...

It took 1.5 hours for me with a regular (hand) screwdriver.

spent $75

PS. to remove the screen I used 2 Ikea’s towel holders."

bert [Entry]

"I would start by testing/replacing the electrolytic caps on the power supply board as this is the cheapest solution, the most common problem, and you have already measured an unexpected voltage on this board. Here is a picture with red arrows pointing to all the electolytics on your power supply board:

Look for any capacitors that are bulging, or even leaking, from the top vent. You can test the caps with an ESR meter to confirm a fault, but isn’t necessary if you don’t have one.

WARNING: Be sure to discharge all caps before messing with them!!! How to Safely Discharge a Capacitor

After this, look to replace the power supply board."

bert [Entry]

"this is what I got apart so far. One on the left 43in works fine. Just busted the screen. Kid hit it playing in the house. Other just stopped working 2 days ago.

Update (03/11/2019)

sorry this is my tags"

bert [Entry]

"Replaced most caps, not the small ones. Wasn’t it. Replaced strips, working—wasn’t it. I have MOSFET’s out, and parts are here but had to take down repair station off dining room table while relatives visited. As yet, I’ve not got to trying them. They’re the little parts under the heat-sinks. I doubt it will be them, to be honest.

I’d suggest anyone who wants to “play” with this television just go ahead and buy one of the cheap ESR meters—I got an MK-328 LCR ESR tester. It was about $25 from China and took a few weeks to get here. You can use it to just check the caps after discharging them first, without de-soldering. Caps are cheap but when you add shipping they get costly this hit or miss stuff.

Frankly, I sort of wish I had just bought another one—I’ve spent half the initial cost already, and more to come. It’s just a question of how long I keep trying. But now I’ve got the tester, which can test the stuff on the board, so when I get back to it maybe I’ll stumble on to a bad part! Wish me luck. I’m due some."

bert [Entry]

"I finally gave up throwing good money after bad.

On the up-side, I did use my ESR meter again a few days ago. I ordered and soldered some new capacitors in an Arris 6141 Modem. That didn’t work either. This “replace the capacitors” thing hasn’t ever worked for me.

I can’t bear to throw the TV away, or give it to BestBuy. I guess I’ll have to at some point.

I’m still watching an older model I had, ironically an LG 42”.

I wish some brilliant person would figure it out and post it. I’d be willing to bet it’s the same bad component—probably just a simple soldering job.

I don’t trust the boards you buy either to be functional."