[drbug1]

Hello to all, I have a problem with an LG 52LG70-UA. Have had it for 3 years and it has been flawless, there have been no changes to our entertainment system in about a year and everything has always been plugged into an APC 1500 theater edition UPS.


2 months ago if you turn the TV off and it would click and come back on again. Irritating, but not a big deal, unplugging it seemed to resolve it most of the time. Then, 1 month ago it started something new, when you turn the TV on, red light comes on, screen lights up, it displays "HDMI1..." like normal, then as it is about to display the picture, there is a click, it turns off, restarts itself, and repeats the same process over again. Sometimes it will do this for 20 min or so and then start working, sometimes it just does it indefinitely. We can still get it running by unplugging the power cord, waiting, plugging it back in, but it is getting worse.


What we have tried:

Switching HDMI ports (same result)

Disconnecting the receiver and attaching a single device (ie blu ray)

Tried using HDMI 1-3 (same result)

Leaving it unplugged for several minutes to hours (Seems to work, but it is intermittent)

Swapped HDMI cable (same result)

Swapped Power cable (same result)

Plugged directly into wall socket (same result)


I have read about capacitors malfunctioning (i'm a network engineer) and I disassembled the TV, removed the invertor boards and the power supply board and found that all of the capacitors look perfect (ie no bulging or leaking). I'm going to take the powersupply board into a local electronics store and have them replace the capacitors anyway. But, does anyone have any experience with this particular problem. I've seen several mentions on AVSF and other Googled info, but no real answer.


Any info would be greatly appreciated!!! Thank you!

 

[GuoJing]

I have the same TV and it has developed the exact same problem. When the TV starts, it has the antenna selected as the input. Before I can change it to another input, the TV clicks, starts up again and repeats. Everything on the power supply board looks good visually.

 

[GuoJing]



Quote:
Originally Posted by drbug1  /t/1419782/lg-52lg70-on-and-off#post_22209138


Hello to all, I have a problem with an LG 52LG70-UA. Have had it for 3 years and it has been flawless, there have been no changes to our entertainment system in about a year and everything has always been plugged into an APC 1500 theater edition UPS.

2 months ago if you turn the TV off and it would click and come back on again. Irritating, but not a big deal, unplugging it seemed to resolve it most of the time. Then, 1 month ago it started something new, when you turn the TV on, red light comes on, screen lights up, it displays "HDMI1..." like normal, then as it is about to display the picture, there is a click, it turns off, restarts itself, and repeats the same process over again. Sometimes it will do this for 20 min or so and then start working, sometimes it just does it indefinitely. We can still get it running by unplugging the power cord, waiting, plugging it back in, but it is getting worse.

What we have tried:

Switching HDMI ports (same result)

Disconnecting the receiver and attaching a single device (ie blu ray)

Tried using HDMI 1-3 (same result)

Leaving it unplugged for several minutes to hours (Seems to work, but it is intermittent)

Swapped HDMI cable (same result)

Swapped Power cable (same result)

Plugged directly into wall socket (same result)

I have read about capacitors malfunctioning (i'm a network engineer) and I disassembled the TV, removed the invertor boards and the power supply board and found that all of the capacitors look perfect (ie no bulging or leaking). I'm going to take the powersupply board into a local electronics store and have them replace the capacitors anyway. But, does anyone have any experience with this particular problem. I've seen several mentions on AVSF and other Googled info, but no real answer.

Any info would be greatly appreciated!!! Thank you!

As per my previous post, my TV started out with exactly the same symptoms as yours. Today after some tinkering the TV is working again. Everything on the boards looked good with no signs of bad capacitors or overheated components. I tried unplugging the inverter boards and applying power and the TV went into standby without clicking. I then plugged in one inverter board at a time to see if the clicking returned and it never did. For some reason the TV started working again. I am leaving the back cover off for now until the TV runs normally for a while.

 

[drbug1]

Thanks for the info, I had my electrical guy look at the power supply board and he said that even though there was no discernable issue just from looking at it doesn't mean that everything is functional. He said that the capacitors on there were of the lowest quality and he recommended replacing all of the small to medium ones, and not the 2 really large ones. So he should have it ready in a couple of days. I will repost after i get it back together.


Thanks for the tip, let me know how it goes with your TV.

 

[GuoJing]

Well, the original clicking problem has returned. I had the TV sitting on the floor with the back cover off for two days, then with the cover on for one day. I powered on and off numerous times and everything was fine.


Finally I put the TV back on the stand and that's when the problem returned. I do not have the time right now to take the back cover off again and It would be a PITA to start swapping out so many capacitors. I wish I had some known good boards to swap out entirely to narrow down the problem.


At this point I am thinking about putting the TV onto a power strip and using that to shut it off. Hopefully it would last until there are some good end of year deals on a new set and this would become my second set in the basement that I would tinker with in my spare time.

 

[drbug1]

Ok just got the board back yesterday, installed it and TV is working great so far. Didn't know how much we missed it. I will give it a few days and see if it continues to work. If it does I will post the exact capacitors he replaced. Cost me $95 to have it done.

 

[GuoJing]



Quote:
Originally Posted by drbug1  /t/1419782/lg-52lg70-on-and-off#post_22262446


Ok just got the board back yesterday, installed it and TV is working great so far. Didn't know how much we missed it. I will give it a few days and see if it continues to work. If it does I will post the exact capacitors he replaced. Cost me $95 to have it done.

Thanks for following up. Please do post which capacitors were changed. I'll try to change mine also when I get a chance.

 

[drbug1]

Sorry this took so long, have been waiting on him to get back to me. He replaced ALL the capacitors EXCEPT the two large ones. I believe the brand he used was VR. We have had no problems with the TV since, fingers crossed. If you would like, give me your email and I can email pics and highlight the capacitors. Let me know. Good luck with yours.

 

[GuoJing]

I appreciate the offer and the information. There are some pretty good pictures online and I can always pull the board to find out the values of the capacitors if I decide to go that route. I found that partstore.com sells a refurbished power supply board for 63.90 with a 30 day return/warranty policy. Though I work in a facility with electrical repair equipment, I would still need to order the new capacitors and install them. I'm thinking I will probably try the partstore option since it is a Best Buy company and not some fly-by-night operation. Either way, I'll let you know what happens. Thanks for your help.

 

[drbug1]

Just to let you know, after almost 3 weeks of no issues, the problem has returned. We were away for a week and TV was off the entire time. Go to turn it on and it is on and off again. If you let it sit for 20 to 30 min rebooting over and over it finally comes up. But, if you switch the source (BluRay -> TV or XBOX) it starts rebooting again. So we are back to square one. Let me know how yours goes. Also here is the parts list from my guy:


3x 2200UF 35V 105* All of these are radial aluminum electrolytic capacitors rated to 105*C

1x 1000UF 35V 105*

2x 3300UF 10V 105*

2x 1000UF 25V 105*

2x 220UF 25V 105*

1x 470UF 10V 105*

1x 100UF 50V 105*

1x 47UF 50V 105*

2x 22UF 50V 105*

4x 10UF 50V 105*

 

[GuoJing]

Sorry to hear that the problem returned and for taking so long to get back to you. I haven't checked this forum for a while. By the time I went to order the refurb power supply board from partstore.com, it was already out of stock and I wasn't willing to pay for a new one. I am still living with the TV on a power strip to shut it off. With the source of the problem still unknown, I will wait for the holidays to replace this one as the main TV. There seems to be no other choice without some spare boards to try swapping out. I am disappointed that this LG TV only lasted 3 1/2 years with no problems. Thank you for sharing your information.

 

[Eric Bartoszak]

I am having the same problem as you guys. Tv turns on and off. power button doesnt work, has to be unplugged by powerstrip. The tv turns on and off till i can select the correct hdmi that corresponds to the hdmi device that is turned on for instance if it is on tv but the cable box is not turned on it will click on and off but if i have the xbox turned on and i can select xbox from the hdmi input selection before it turns off it will stay on and i can play xbox. it started progressively getting worse so i called a tv repair guy to come take a look and he didn't notice any problems with capaciters. no buldging or anything. he wants to come back and take another look at it, maybe do some further research into problems before he starts replacing parts without def knowing the problem. If anyone figured this out please let us know. And on a side note LG is a te3rrible company for customer service because they wont even admit that they have ever heard of this on/off problem regarding this model. Terrible Just terrible!

 

[Marc Malenfant]

I have also started having this issue. Contacting LG customer service confirmed that they deny any knowledge upfront and recommend calling in a service technician.

From researching online I was almost positive it would have been bad capacitors, but now after finding this post I am dissapoint.

 

[drbug1]

Hi, I just wanted to follow up on this. So as mentioned above, since replacing almost all of the capitors on the power supply, the probem went away for a few weeks and then returned. I then decided to purchase a new mainboard on ebay. After going through about 3 mainboards (they are built based on the screen and LG used different manufacturers for the screens, so there is a particular mainboard for each screen) found the correct one, installed it, turned on TV and whalla: same problem. By this time I'm so deep into fixing the TV I am like, oh hell why not keep spending money on it. So I ordered a new power supply, and whalla: problem fixed. I have found other posts about this issue and it might be a resistor that needs replacing instead of capacitors. Like others, my capacitors looked perfectly fine before replacment and after made no difference. Take a look at the last post in this thread: http://www.edaboard.com/thread121910.html There are only a few resistors on the PS, so it would be worth replacing them to find out.

 

[itisjustmoi]

I too have the same issue, it started quite sometime ago and got progressively worse, googled lots of sites and found that many people have the same issue. LG support first said that it was out of warranty, then gave me an extended one. I had it repaired and the problem came back again in less than a month. I contacted LG and they wouldn't fix it again and became completely non-responsive and noncommittal.

After googling again I replace the power board, no change and then replaced the main board, actually got worse. Both those boards were new and were matched to the existing board's PN#s for compatibility.

It's too bad, nice picture but basically scrap now. I just bought a new TV to replace it, NOT LG. I won't ever buy one again simply due to them not acknowledging that there is a basic design flaw. Heck, my parents still have a 60's color TV that still works.

 

[Sarah Burks]

hello. . I see this was posted last year but I have the same problem. . and I have an lg 52lg70. . I think I read further down you replaced the entire power supply. . . but I just wondered where you found or bought one. do you think I should start by replacing the capacitors. . . don't laugh but are those the ones listed in one of the replies?? I was trying to do all the leg work for my husband he works 6-7 days a week. . . and even order the parts if I can find them. . . I just am learning as I go . . . thank you for any help you have.


you press the on button and it's red and then just clicks on and off. no picture or anything and you have to unplug the tv to turn it off. . . from what I've read this is a very common problem that LG refuses to fix??


thank you for any and all help. .


Sarah

 

[drbug1]

Hi Sarah, sorry to hear about your TV! I got my new powersupply on ebay. Look for the seller tvpartexpress, they are GREAT! Good tech support, super helpful. Frankly, unless you are experienced with soldering and are comfortable taking your TV completely apart and putting it back together possibly several times (or dozens like I did), I would recommend paying the $100 +/- for a new (or rebuilt) power supply. It's worth $100 to get a couple more years out of a decent TV and replacing the power supply is not that difficult. Mine is still working (so far)! And yes you read it right, my guy replaced 19 capacitors on my board which was an improvement, but did not fix the problem. I still have my old power supply and a replacement main board, that I need to get rid of, just realized that.


Good luck! Let me know.


These were the capacitors he replaced.

3x 2200UF 35V 105* All of these are radial aluminum electrolytic capacitors rated to 105*C

1x 1000UF 35V 105*

2x 3300UF 10V 105*

2x 1000UF 25V 105*

2x 220UF 25V 105*

1x 470UF 10V 105*

1x 100UF 50V 105*

1x 47UF 50V 105*

2x 22UF 50V 105*

4x 10UF 50V 105*

 

[Juggernaut321]

Hello everyone. I need some help and I know this is kind of a old thread but here goes. Trying to help my sister out and fix her 52LG70 LG HDTV. One of her little girls thought it would be fun to splash apple juice on the TV. Well the apple juice got on the right bottom corner of the screen and ran down inside of the set. When it first happen the bottom ¼ square of the screen went black. Its been sitting in her house for about a year. I told her I can give it a shot. Now I just turned on the set and you can see the screen light up and hear sound but no menu comes up when you hit menu. Could this be a bad inverter board?


Thanks for the help.

 

[olasrider]

I have the 52lg70 and had the same issue start at the three year mark and just deal with it by unplugging it after watching but now that isn't working. I'm not as savvy as the people on here so ilk but I new tv but this is total BS and LG should have supported their products better.

 

[Murmur]

Add me to the same boat. At first we had problems turning the tv off and now we have the common issue of the tv clicking on and off repeatedly. Sometimes it goes on the first time, another time it could take 5 - 10 minutes before it goes on. From what I have seen, replacing the power supply seems to be the solution - would this be my best bet to start?


Thanks.