LG LCD TV 42DL550 Fix

How to repair an LG LCD TV main board.

 

This is a simple method to fix a TV or other electronic device with bad solder connections.  The TV I fixed is an LG 42″ LCD TV Model 42LD550-UB.CUSWLHO.

Symptoms

The TV would power on and the LG Logo screen with the clock would appear.  It would freeze on the logo screen.  It was stuck there and would not boot any further.  The none of the buttons would work.  It was totally stuck.

First I tried unplugging it for about 15 min to reset everything, but that did not make a difference.  Note:  It’s always good to try this first on any electronic device.  Also if the device has any kind of factory reset button, always try that as well before taking it apart.

I searched around online and found other people reporting issues with this TV.  HDMI ports not working, no inputs working, Lines on the screen, fuzzy video, etc…  It seems many different makes and models are affected.

I removed the board and I did not see any physical damage, no components looked fried or burnt, no capacitors looked bad, and all the connectors looked to good.  This lead me to believe the main control board Model EBT60955753 LG MAIN (3642-1052-0150) could have one or more bad solder joints.

This TVs was purchased in 2010 and out of warranty.  A new board was hard to find, and too expensive.  I decided to try this simple repair myself because I had nothing to lose!

Summary

To fix it, I baked the main board in a electric oven for about 10 minutes at around 385 °F and It worked!

Explanation

Why did this work? After heating and cooling for years, tiny cracks can form in the solder connections.  Heating the board to 385° F (above the solder melting point) caused the solder to melt and these cracks flow back together.

Believe it or not, this trick works on more than just this TV.  This can fix a long list of other electronics.  It’s not uncommon for manufactures to under cool their components, and/or ship electronics with bad solder.  Poor ventilation, bad fans, small heat sinks, dust, stress, and other factors can also cause over heating or cracked solder points.  Even a very tiny crack that you can not see can cause a bad connection.

Warning:  Attempt at your own risk!  Safety First! Always wear protective gear when working on electronics.  Safety Glasses, Gloves, etc…  Remove Electricity from the device (unplug) to Avoid Shock!

 

Again, attempt at your own risk!  This will void your warranty, and possibly damage the board.  I have only tested this on an LG 42DL550!  Other readers have had success on different models so search through the comments.  I would only try this if the TV is unusable and you have nothing to lose!


Let’s Do This!  Step-By-Step DIY Fix:

 

– Remove the board from the TV

LG MainBoard EBT60955753 (3642-1052-0150)

LG LED TV Control Board EBT60955753 (3642-1052-0150)

  • Step 1.  Call LG and complain.  Everyone complaining to LG might make them understand how unhappy people are, and they’ll see this is a known issue!  Maybe if you play your card right, they will admit this is a fault with their product and send you a replacement.
  • Step 2.  UNPLUG THE TV before you touch it!  Electric shock can cause death!
  • Lay the TV down on its face. (Put it on a blanket to be careful not to scratch the LCD)
  • Remove the stand from the TV. (remove the four long screws at bottom and the stand slides out)
  • Remove the back cover from the TV.  (don’t forget the screw near the power plug, and the one in the middle of the input jacks.)
  • Take pictures of the Board from all angles.  Make sure to get good ones of all the connections.  You can use these pictures later to make sure you reinstall it correctly.
  • Remove all the connections. (Be gentle, they should come off easy, if you are doing it correctly)
    • How to disconnect them isn’t obvious to the inexperienced.  Use the picture above for reference. (Click on the picture to enlarge it!)
    • On the upper right there are two ribbon cables. To disconnect these, gently lift the thin black plastic strip on the connector (it flips up), then you can pull the ribbon cables out.
    • On the lower right there’s a wide header block with gray wires. Squeeze the sides (opposite ends) of the connector to release it and pull up.
    • On the upper left are two other connectors. In the center of these is a small plastic part. Press down gently on the edge of that (the edge near the wires), causing the opposite edge to lift a bit to unlatch. While pressing, pull gently in the direction of the wires, away from the board.
  • Once all the wires are disconnected remove the six (6) screws holding the main board to the frame.
  • Remove the black plastic face plate from the side input jacks. (No screws, it’s held on by it’s plastic clips).

– Bake The Board

  • Now we are going to bake it in a conventional electric oven.  (Do NOT use a microwave, gas oven, open flames, Air Forced Heat, or any other type of heat!)
  • Why not use a heat gun?  A heat gun is forced air like a hair dryer.  As soon as the solder melts, the air will blow the components out of place, or even go flying off the board.
  • Why not use a gas oven?  Open flames can be dangerous in this situation.
  • Why not use a microwave?  Never put metal in a microwave!  Very bad things can happen.
  • Preheat the oven to 385 °F (196 °C)
    • The correct Temperature is IMPORTANT.  If you don’t trust the temperature setting on your oven, or if your oven does not have a temperature setting, then get a baking thermometer and test your oven!
    • 385 °F is working for most people, but there are different kinds of solder.  Altitude and humidity might also play a factor.  Most solder melts between 360 and 419 Degrees Fahrenheit or 180 – 215 Degrees Celsius.
    • Solder is a mixture of Tin and Lead.
      50 Tin/50 Lead: melts between 183–215 °C (361–419 °F)
      60 Tin/40 Lead: melts between 183–190 °C (361–374 °F)
    • NOTE:  These temperatures might sound scary, but the ignition temperature of paper is around 451 °F so these components should not be damaged at these temps in an electric oven.  Again, this is why we only us an electric oven.  No open flames!
    • See https://en.wikipedia.org/?title=Solder for more details about Solder.
  • Place the board face up on something nonmetallic like a piece of cardboard.  A pizza round or similar works well. (Do not put it on anything metal because the solder will stick to it.)
  • Place it on the center rack of the oven.
  • It will smell funky when cooking so you might want to open a window and/or turn on a fan!
  • Let it cook for about 10 min.
  • Turn the oven off and let it cool.  (Be careful!  It’s hot and will burn you!  Use oven mitts!)
    • Do not to bump or disturb it while it is cooling!
    • I would not move it until its below 300 °F, so you don’t disturb any components!
    • Just turn the oven off and leave the board in it with the door open until it’s cooled off a bit.
    • If you take it out of the oven while it is still hot, remove the board very carefully, let it cool at least 30 min before you touch it.

– Install and Test

  • Install the main board in the reverse order that you removed it. (Refer to your pictures)
    • Make sure you get all the cables in the correct location.
    • Double check each cable to make sure it’s connected correctly.
    • Check your pictures to make sure you have everything correct.
    • You might want to leave the back off until you test it in case it doesn’t work, and you need to bake it again. Just do NOT touch anything back there with it plugged in!  BE SAFE!
  • Turn on the TV and see if it works.  (Note:  Wait at least 10 Seconds after turning it on because it seems to take a long time for this particular TV come on.)
  • If it does not work:
    • Try cooking it again for 15 min.
    • 10 min. worked for me on the first try but results my vary…
    • Try a higher temperature 183 – 215 °C (361 – 419 °F) as noted above.
    • One reader noted he went all the way up to 482 °F (250 °C ) although I highly recommend staying below 425 °F.  I’m guessing his oven settings are off.
    • Another reader said he put a weight on the LVDS chip while baking and that worked.
    • Read through the comments, there’s a lot of good info in there.

Please comment to let everyone know how it went for you!  Include the Make and Model of your TV / electronic device to help others can find this post!

Warning:  Attempt at your own risk!  Safety First! Always wear protective gear when working on electronics.  Safety Glasses, Gloves, etc…  Remove Electricity from the device (unplug) to Avoid Shock!

 

Again, attempt at your own risk!  This will void your warranty, and possibly damage the board.  I have only tested this on an LG 42DL550!  Other readers have had success on different models so search through the comments.  I would only try this if the TV is unusable and you have nothing to lose!

 

Keywords:  Samsung, Sony, Vizio, Sharp, Sony, Insigina, Toshiba, JVC, Philips, Magnavox, Sanyo,  Fix, Electronics Repair, Motherboard, Mainboard, ControlBoard, CPU, ReSolder,

463 thoughts on “LG LCD TV 42DL550 Fix

  1. Thank you! My 4 hdmi ports all stopped working a couple of days ago and nothing would fix them. I just followed your instructions this morning and now they all work again 🙂
    42LD490 from 2010 or 2011.

  2. I baked my LG 55le5400 main video board 3 years ago to fix the HDMI non-working ports and it worked up through yesterday.
    Now, my TV has a blank screen but the power light is on. All buttons on the remote and on the TV front do nothing. So I baked the board once again (385 for 10 minutes) and it started up with slow motion and darkened blur on the screen which stayed that way even after repeated tries.
    I took the board out and baked again and voila! Perfect picture and all the HDMI ports are working again!
    By the way, the horrible toxic smell from baking is a lot less the 2nd and 3rd time around.

  3. Another happy customer! I have an LG 42LD550 from May 2010 that stopped working a couple months ago (after powering on, it would freeze on the splash screen). Tried all the resets suggested in various posts, including the two push buttons on the main board, but none worked. Baked for 10 minutes at 385F, turned the heat off and let it cool to the touch. Reinstalled and presto, I have my TV back!

    Thank you for a truly useful post – like others, I joined and donated some $ to show my appreciation.

  4. My LG 50PZ550 plasma stopped recognizing HDMI sources last Friday. I performed the bake here exactly as instructed, especially letting it cool before touching anything. TV is back to normal now. Upon first reassembly, I wasn’t getting a menu, input selector screen, or any image. I was worried I had ruined the TV (well, even more). But I hadn’t felt right about re-clipping the blue ribbon cable back in, that’s the one where the gate clamps down on the cable. I reseated that and that issue was resolved.

    For those wondering, as a test, before removing and baking the board, I unhooked every ribbon cable and let the board sit for 10 minutes. I plugged everything back in and the problem did not go away…I was wondering if it was the simple disconnecting of the board, maybe from a biOS battery or something? that had reset the HDMI handshake, etc.

    1. Well now the TV has a different issue. It will power on, and for just a moment I will see the TV channel image on the screen (I will see the tv program). Then the screen will lock up with static vertical lines or a near whitewash. The audio will keep going. I can change the channel on the ATSC tuner and hear the new channels. I can use the Eco button to make the screen brighter or darker, or turn off altogether (sound continues). I can change inputs too.
      So the tv keeps working except the screen is bonked. I left it on the brightest setting for 30 minutes to warm up, the powered on and off a few times and eventually it *mostly* worked, just with some stuttering and glitching near the top and a few lines across. Would this still be a main board problem, or more of a Ysus or Zsus issue? I have the service manual, I plan to check the voltages with a multimeter.

  5. I was skeptical about this, but it came to the point I either try this or toss out my tv. While it was in the oven, my granddaughter asked me what I was cooking – I told her I was baking my tv – baking your tv!? she replied – I said “haven’t you ever heard of a tv dinner?” lol – but more funny than that, is that now my tv works – so far so good and its been abt a week 🙂 – I still can’t believe it 🙂

  6. This works for me every time. I will say I do have to repeat the steps every 4-5 months but in my opinion it’s worth it rather than having to go buy a new TV. I got my 55” for free because it wasn’t working. Now it does 😁

  7. I created a login just to comment on this. This fix worked for me! I have a 47″ Samsung LED from this era, and I was skeptical at first, but it worked like charm! Thank you!!!

  8. Like previous people I created an account to say thank you.

    I had what looked like a standard capacitor fail on my LG LCD TV 42DL550 TV. I searched the power board with no obvious failure. The reason for fixing it is it is a 3D TV and these are impossible to get given the changing trends in the market yet I am stuck with a bunch of worthwhile 3D titles.

    I spent $215 on a new power board. FAIL!

    This was my last resort.

    After following the instructions to the letter my only words are THANK YOU.

    If you have a last resort board where you have tried everything else, you have nothing to lose and remember the difference between F and C.

    Again thank you.

  9. I almost never post comments or replies. This was GREAT help.
    LG plasma 3D TV I purchased 7 years ago. HDMI stopped working. I hooked up a component cable and only got audio. Darn. TV is dead. Better Google it.

    I stumbled upon this page and did as instructed. What the heck, TV is dead anyway. Easy to do. Opened it up and took pictures. Removed the board. Baked it 10 minutes. (Put it on a piece of cardboard) DING! TV is done.
    Put it all back together. Also very easy.

    The picture is phenominal and all of the inputs work great. THANK YOU SO MUCH for the fix that made me a TV tech superhero instead of a guy with a TV in the trashcan.

  10. I too want to say thanks. I have a 60 inch LG plasma 3-D TV. At about five years old, I started getting weird color splotches on my screen. Thanks to the Internet, I found out it was bad solder on the Y-sustain and Z-sustain boards. If you have this problem, go to:
    https://www.avsforum.com/forum/167-plasma-flat-panel-displays/1621890-lg-60-plasma-flickering-changing-colors-splotches.html
    The problem and the solution is discussed in detail. It was maybe 10 minutes of soldering fixing obviously cracked Solder Connections. Had I known about the “Oven fix”, I might’ve just put the boards in the oven. 😉
    I was so happy when the color splotches went away. As I was testing everything, suddenly the HDMI ports stopped working. I figured I had broken something with my soldering. I found that the analog ports worked, so I just hooked up component cables instead. I did find this article, but since I had a working solution I figured it was better to leave it be.
    A couple years after the first fix, The TV suddenly went dark and I could not even get a menu option to display. However, I could see the plasma activate and I could also hear sound. When googling that condition, the primary suspect indicated was The “main board.”
    With nothing to lose, I once again removed The insane amount of screws that LG uses for the back cover, carefully removed the main board, and baked it according to the recipe. After letting it cool down to room temperature, I carefully reinstalled it, but really did not expect anything positive to happen.
    But lo and behold, the first thing I saw was the spinning LG cube! All the HDMI ports were now working, so I put it back together and The picture is as good as the day I bought it.
    The one thing I lost with switch to component was ability to do true 1080P 3-D from my Blu-ray player. With the HDMI port working, the Blu-ray to TV handshake was restored and I could once again brag about a feature that I never use 😉
    Anyway, thought I would share the color splotch problem and solution since LG apparently has a class problem with the solder they used several years ago. Hopefully, they have that fixed. I also have a couple of LG air conditioners and they have been rock solid over many years.
    Unless there is something on those sustain boards that might melt with the oven fix, I would probably try that solution unless you are comfortable using a soldering iron. The sustain boards are quite a bit larger than the main board , but you should be able to get both of them in a standard oven I would think.
    I will be curious of the fix holds up. I saw one comment about having to do it every six months 😳
    For what it’s worth, The solder fix on my sustain boards has held up for about three years now, so I’m hoping the main board “oven fix” will hold up as well.
    Thanks again for the excellent suggestion and it’s something I might try on other electronics when all else has failed.

  11. This fix totally works!!! Moved our old LG 46LD550 from our living room to our loft for the kids after buying a bigger unit. Got the Fire TV Stick all setup so they could watch movies and it was working fine, then yesterday it flickered and failed. Component video worked fine. Did all the reset, power disconnect tricks, but nothing worked. Wasn’t too sure about pulling the board off and baking it, but will all the positive results posted here I figured it was worth a shot before buying a new TV. Carefully followed the step here and sure enough, we had success! My kids are stoked and Dad is the hero. Thanks!

  12. Just wanted to comment that this method worked for me too. I picked up 42LE5400 for next to nothing at a local thrift shop. I was warned by an employee that the fellow who dropped it off said that some hdmi inputs were inoperable. While displayed in the store, I was able to verify that one of the 4 inputs were working. However, once I brought it home, all inputs were not connecting. I tried for a week off powering down and reconnecting the TV with no success. After searching the internet and landing on this page, I thought I’d give this method a try. I removed the A/V input daughter board and placed it on cardboard in my gas oven for 15mins at 400 deg F. Even with an exhaust fan there were some fumes present but not unbearable. I was worried about the open flame of my oven but nothing extraordinary happened. After letting it cool in the oven for about 45mins, I reinstalled the board. I let the TV sit for 8hrs before I powered it on. After powering on I was surprised to find that my hdmi inputs appeared to work now! Thanks for all of the detailed information.

  13. Hello, I have an LG4LH50 where, like many others here, the 4 HDMI ports stopped working. I saw several things online including using a hairdryer. The hairdryer did not work for me, but I was able to follow these directions and bake the board. I did remove a plastic piece from the board that seemed to be a spacer for the back before baking it as I thought it might melt. It was tough to get out; I had to use needle-nosed pliers. I baked it on a piece of cardboard so the solder would not stick to it. I opened the oven and let it all cool about 40 minutes before moving it or touching it like stated above. It was all cool to touch and not warm at all. I hooked it all back up and tried it before putting it all back together. IT WORKED!!!! WOOHOO!!! I put it all back together, and we are good to go. Thank you very much for your help!

  14. So my LG tv stopped working for it’s HDMI ports this week. Time to bake some TV. Let start by saying that about 2 or three years ago the TV stopped working and All I got was the splash screen and then nothing. I searched and found this posting. I had nothing to lose, since it was already dead, so I tried it. Sure enough the TV was back to life.
    Now 2-3 years later it dies again, but obviously different solder points as it is different symptoms. Well yesterday I took it apart and baked it again. It took me less time for the whole operation this time around since I already knew what to expect and how to release all the connections properly. When I reassembled it I had my old set back. But seriously if this dies again it may be time for a new set. My wife complaining about the plastic burning smell afterwards, Which lingered into the night even though I had windows and the back door open for a few hours ( in 42F temps) might just make the difference.
    I will add that I have a gas oven and no access to an electric oven and found that everything went smooth so I don’t know why that should be a concern, If you are using the middle rack, as you should, then you are never going anywhere near the flames.

  15. Thanks so much for documenting this process.

    It has worked for LG 50PK590 plasma TV that I bought in 2010, and for which three of the four HDMI ports, the aerial connector and the speakers had stopped working.

    However, something else has gone wrong when I disassembled or reassembled the TV, and I’m hoping someone can help, as I haven’t found any similar problems in the comments.

    Whenever I turn the TV on, it takes a minute or so to go from a completely blank screen to the white ‘snow’ of an untuned analogue aerial feed, with all the other settings reset to factory default; the HDMI connections are unnamed, the picture is set to Vivid, the volume is 0, etc. It also doesn’t turn back on well – sometimes it will respond to the remote, but other times it requires turning off at the plug before turning back on.

    I’ve opened it up again (in part to resolve the speakers, for which I hadn’t reattached the connector properly) and checked the connectors, but I think this may originate from a different circuit board (or I’ve fried the circuit or battery that stores settings on the board I ‘cooked’).
    I’ve also tried both setting some or all of the settings, and running a factory reset before setting them, but neither worked.

    Please let me have suggestions on how to resolve this.

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