Help needed! LG 47LV5500-UA with no video or audio

[Is9582]

Hello all,

As I wrote in the title, I own an LG 47LV5500-UA that we bought in 2012. My wife and I were watching some of the early 2018 Olympics and during the broadcast, it just went dark and emits no audio. We weren't having any weather at that point, so it just seems as though it reached its limit. When trying to turn it on, after it cut off, the red indicator light is initially on, but turns to a white light after I press the remote's ON button.

I have some electric experience via my old side business where I repaired old tube guitar amps, as well as modding some of the same. I even worked on and repaired a couple of solid state guitar amps, while I had a relationship with one of the local pawn shops, but my focus was on the tube gear.

I did a quick search online after the TV died, and saw there were a number of reported instances of similar occurrence for this exact model of TV. Some seemed to get them going again by what sounded like applying heat to the main processor on the video processor board (probably not the correct name, but I am a noob).

I'd really appreciate any guidance as I'd love to repair this TV if possible. We already purchased its replacement, but I can hand it off to one of our kids, if I can get it going. I still have a good DMM, as well as some other gear, but know so little regarding TV repair, especially with no schematic or repair guide.

Thanks in advance,

Lee Laird

[tvtimmy]

Re: Help needed! LG 47LV5500-UA with no video or audio

You need to have the bga chip on the main board reballed. You can try heating it up with a heat gun on low for about 45 seconds. You need to remove the heatsink first.

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio

Thanks @tvtimmy ! Is there any tricks to removing the heat sink? Just so a ham fisted guy like me doesn’t do irreparable damage while trying to fix. Also curious if There are any visual indications regarding success? Or is it just a matter of reinstalling the heat sink and testing the TV? Appreciate the assistance!

Cheers

Lee

[tvtimmy]

Re: Help needed! LG 47LV5500-UA with no video or audio

There are 4 push pins that hold down the heatsink. Squeeze from the backside and push them up. There is a rubber pad that might stick to the chip or the heatsink. Take it off the chip.I use an old wagner heat gun with a home made reducer tip thats about a 1/4" blow hole. Set it to LOW so you dont blow off all kinds of small parts. Go over the whole chip and let cool. Put all back together and turn it on. I have fixed many LG tvs this way. Nobody knows how long it will last butI only had one come back to me.

[freakaftr8]

Re: Help needed! LG 47LV5500-UA with no video or audio

There are 4 push pins that hold down the heatsink. Squeeze from the backside and push them up. There is a rubber pad that might stick to the chip or the heatsink. Take it off the chip.I use an old wagner heat gun with a home made reducer tip thats about a 1/4" blow hole. Set it to LOW so you dont blow off all kinds of small parts. Go over the whole chip and let cool. Put all back together and turn it on. I have fixed many LG tvs this way. Nobody knows how long it will last butI only had one come back to me.

Toshiba's are horrible for this as well. Don't think I ever had a Toshiba that didn't need a heat reflow.

If you have a infrared thermometer make sure to be between 225 and 235 deg. C for 3 minutes. Then pull away and let air cool until cool to the touch.

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio

Thanks again @TVtimmy ! I came in to work on it some more and had an idea that I should just plug it in and test it, since it's been plugged into power since 2012. Sure enough, the main LG screen came up and then showed which HDMI was chosen. I unplugged it and screwed the back on. Plugged it back in and, yep, back to the black screen like before. I only post this on the outside chance that this might be indicative of some other diagnosis. I'll be unscrewing all of the dang little screws again tomorrow. lol

@freakaftr8 Thanks! I do have an infrared thermometer, so I'll make sure to monitor the heat between 437F-455F (translated as I'm not positive if my thermometer can change between C and F. Certainly appreciate your input!

Cheers,

Lee

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio

Just before heading to bed, I decided to try the TV again, since I'd unplugged it on its last fail. Not too surprising that it again failed, but I noticed something that I'd overlooked earlier. When I plugged the TV into power, the red standby light came on, but only for a second or two, then went off. When I tried turning it on via the remote, the red standby came on, and then shifted to a white light. When turned back off via the remote, it shifted to the red standby for a moment, then no light at all. I'm curious if this is indicative of any possible alternate diagnosis, or if it still fits into the bga needing reflowing? I plan to proceed with the reflow later in the day, unless I get input shifting my focus.

Cheers,

Lee

[tvtimmy]

Re: Help needed! LG 47LV5500-UA with no video or audio

Cook that sucker, you got nothing to loose.

[nomoresonys]

Re: Help needed! LG 47LV5500-UA with no video or audio

If you want to check the power supply board with your meter there's little legends/maps, that tell you what voltages to expect from the connector pins.

[nomoresonys]

Re: Help needed! LG 47LV5500-UA with no video or audio

https://www.youtube.com/watch?v=TELvc0thP34 how to test power supply video.

[nomoresonys]

Re: Help needed! LG 47LV5500-UA with no video or audio

http://www.shopjimmy.com/lg-eay62169...upply-unit.htm good picture of the power supply, double check to make sure it's the same one you have, can click the image to magnify pic.

[R_J]

Re: Help needed! LG 47LV5500-UA with no video or audio

Check the voltages on the power supply connector going to the mainboard, are the voltages there when it quits? ie 12 volts and 3.5 volts

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio

Thanks @tvtimmy !

[mmartell]

Re: Help needed! LG 47LV5500-UA with no video or audio

Before you attempt a reflow which can easily go badly just use a hairdryer on the processor for 30-45 seconds or even longer. If the symptoms change then it's possible the main processor is guilty.

[nomoresonys]

Re: Help needed! LG 47LV5500-UA with no video or audio

before you attempt a reflow which can easily go badly just use a hairdryer on the processor for 30-45 seconds or even longer. If the symptoms change then it's possible the main processor is guilty.

+1

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio

@tvtimmy @freakaftr8 @nomoresonys @R_J @mmartell Thanks everyone for your assistance and input. I finally was able too get back to the TV and got her going again. Voltages looked fine so pulled the green board, removed the heat sink from the main processor, and using my heat gun, used a focused but somewhat pulsing heat on the processor. Let it cool back down and back together she went. I tested it before the back was screwed back on, and then again afterwards, just to make sure. Who knows how long this will last, but I’ll repeat the process in the future if/when needed.

Cheers all!

Lee

[nomoresonys]

Re: Help needed! LG 47LV5500-UA with no video or audio

Nice, thanks for the update, it's a shame how many people just never report back.

[Is9582]

Re: Help needed! LG 47LV5500-UA with no video or audio (Resolved!)

@nomoresonys Thanks!

It just felt like the right thing to do, to me (although I have to admit I used to write monthly woodworking articles in a semi-professional capacity, so maybe I'm the odd bird?) especially since quite a few people (you included) took the time to assist with my unknown issue. I'm really grateful this forum and its users are here, and willing to share such valuable knowledge! I consider it a great resource and I've already shared its usefulness as well as name/url with a number of friends/family.

Cheers,

Lee Laird

[freakaftr8]

Re: Help needed! LG 47LV5500-UA with no video or audio

Glad to hear! Thank you for the update