LG LCD TV 42DL550 HOW TO REPAIR AN LG LCD TV MAIN BOARD

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. 

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!

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!

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Let’s Do This!  Step-By-Step DIY Fix:

– Remove the board from the TV

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!