Lightning strike killed the LG 55LW5700 TV - Fixed it!!!!!

This post is about repairing a LG flat screen TV.

Last night we heard a really close lightning strike that blew three breakers in our house.  It killed everything that was connected to my wired ethernet network.  It killed the FIOS box, my desktop computer (which was behind a surge protector), my ASUS wireless router, my son's desktop computer - just the ethernet port, the ethernet port on the Sony TV, and worst of all my fairly new LG 55LW5700 TV.

The LG 55L5700-UE TV is dark.  The standby light blinks slowly red about once a second.  Pressing the power button makes the light turn solid red.  No picture, black screen, no sound, no other life.  Pressing again and back to flashing slowly red.

I did buy this at Costco, less than 2 years ago.  I could take it back and play dumb and say that it just doesn't work.  However I know it was killed by lightning which the warranty doesn't cover.   Ethics aside, the kicker is that it is easier for me to fix it by swapping a board then haul it to Costco or ship it anywhere for repair.  It is a friggin 55" TV.

I suspect the power supply board, given the known power surge.
http://www.fixya.com/support/t17617660-red_flashing_light_tv_power_went_out
Some worries that the strike clearly traveled through my ethernet wires as well, my router was blown, and the set is using wired ethernet.   I might be replacing the main board too.

Found a couple boards around the net that say they are for the set, but part numbers vary.  The picture looks consistent.

• http://www.shopjimmy.com/lg-eay62169901-power-supply-unit.htm

• LG 55LW5700 POWER SUPPLY EAX62876201/8 http://www.ebay.com/itm/330850589833

• LG 55" 55LV5400-UB 55LV355B-UA 55LV3700-UD EAY62169901 Power Supply Board(BX2)

To open up the set and check the board, I'd have to take it off the stand, unwire it, and remove about a dozen screws while I balance it on edge.   While that is unavoidable, I don't want to take it apart and let it sit there propped up for 3 weeks waiting for the part.  I'm going to pull the trigger and buy a new board without really testing or even opening the set to see which exact power supply I have.   In engineering we call this being a cowboy.   I'm going to make a 40 dollar gamble that this is the problem and that I'm buying the right board.  If it is totally wrong I can resell it on ebay.

Finally bought this one.   I'm taking a risk that it isn't the correct board.  Paid $59 + 12 shipping.  I had bought a cheaper one, but the seller cancelled the transaction saying the board was cracked.
BRAND NEW GENUINE LG POWER SUPPLY BOARD P/N EAY62169901 55LW5600UA EAX62876201/9
http://www.ebay.com/itm/271212434286?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Waiting for the new board to come... then I'll post pictures of replacing it.

The board came.


Took the TV off the TV mount and removed the brackets.   Took it down and leaned it against the sofa, so that is was still standing vertically with the screen against something soft.   NEVER lay a set like this down flat on it's face.   The glass can't support the weight and may crack.   Then I removed all the screws around the perimeter of the set.  Must have been 20+ screws.  this is the S/N tag.


The screws are all around the outside edge, and a few around the patch panel on the right.


The only tricky part is that there are a couple screws around the video connections, and the one I missed is in the middle of the RCA video plugs.


Once they were out the back comes right off.


The power supply board is right on top in the middle.


Squeeze the two sides of the power connection and it slides out.


The connectors slide out.  There are two types.  Some you squeeze the two sides and slide it out. A small screw driver can be used as a mini crowbar to separate connectors while you squeeze with the other hand.


  The others have a tab in the center you need to lift to unhook.


Luckily the part number of the power supply board was the same as the one I had bought, EAX62876201


I did notice that the new board is actually an older rev, Rev 1.0 vs the board in my set was Rev 1.1.   They look pretty identical so i'll forge ahead.


I put in the new board and powered up the set.  FAIL.  The set is doing the same thing.  The red light flashes and nothing else works.   You would have thought it was the power supply board zapped, but the surge hit the Ethernet on all the other devices so I should have known it was the main board.

This is the main board on the right.  It has a number of similar connectors requiring squeezing the outer edges and a handful of screws to take out.   The ribbon connectors on the left were the hardest.  Again squeeze the tabs on either side and use a small screwdriver to separate the connector.  Stick the screwdriver in a crack and wiggle and turn it.  A little finesse and they are out.



Here is the part number of the main board.


Found one on Ebay for $73.  Waiting for it to come.  Note that all these LG sets use the same board so it really doesn't have to come from the same type.
http://www.ebay.com/itm/261225522164?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

The new board came today.   It looked pretty much the same as the old one.  I didn't take the time to compare it exactly, I ran down and popped it into the set.  Attached the board with it's screws and slid in all the connectors.

It was not that exciting or difficult to install.   I plugged in the set before putting the cover back on.  Red light was no longer blinking.  Pulled out the remote, pressed power, and baaadaaaaaabing!   Win!  Set came right on, and the picture was there.  I had to reset up everything because of course, with an all new board it had forgotten all the internet SSID, Netflix passwords, etc.

The hardest part was actually getting the cover back on.   I propped the TV set up against the sofa and worked on it vertically since you never want to lay a big TV flat.   When i put the TV back on, it was tough to line up the screws and keep the front plastic bezel from popping out.   I had a couple extra screws when I was done.   Once I slipped and the set almost fell over.   However all was good.

Since the board was from a 47LW5600 not a 55LW5700 I need to go into the service menu and reset the set type and turn on some of the features, like the audio settings.  I covered that in another post, you need the correct universal remote and the password.   This isn't absolutely necessary, the TV works fine it just thinks it is another model.  Some of the video modes, local contrast options are turned off.
http://blog.workingsi.com/2012/02/hacking-lg-55lw5700-tv.html

My new RCR312WR.  See the Guide button.

Put in the 5 digit code 11265 on this one.  Hold the TV button and type it in.  

Went to the TV and pressed the guide button.   Enter 0413 as the password. 

Press guide and the code box pops up.   Type 0413

Adjusted the TV model and size back to 55" and turned on the picture modes, audio, etc.

Anybody with  Philips head screw driver, some patience and an Ebay account can do this repair and amaze your friends.  Even other electrical engineers were amazed I took this on.  You have to have faith that sets are modular and easy to open and swap boards.  If they weren't they'd cost the manufacturer tons of money. Back in business for <$160.   It might have been half that if I had replaced the main board first.  I could resell the power supply board, but I'd have to put it back in and prove it was good before I could sell it, and I want to get on with life.

Since I did this I did some more googling and there are youtube videos on the process, which i haven't looked at.