LG 50″HDTV 50LN5400 No picture With sound repair

Last week went outside to see neighbor throwing away a 50″ LED/LCD Television that appeared to be in excellent shape.
After asking if it was okay to take and observing the TV it was basically like new “Manufactured late 2014” with exception that it did not get a picture when the TV was powered on.
It powered on fine and even had sound just no picture.
First thing you do is try to force start it.
This requires you to press buttons on the TV at same time which in this case was pressing both the ok & Power button at the same time for about 15 -30 seconds then power off TV and restart if all is well the TV will then power up with picture & sound.
Every TV is different some require the remote and the TV buttons to do the force power up.
Read manufacturers info to get this combo. Some don’t offer the force power up option I know Vizio televisions do not. Atleast the Vizio’s I’ve worked on don’t there may be some that do.
If nothing changes after force power up you will need to go right into the TV and start checking currents.

If it does power on with picture. Look at the picture is it dim in some areas are there lines or any discoloration?
How long does the TV stay on? watch these things it helps with troubleshooting the issue or issues.
After this unplug from the wall wait 15 minutes plug back in and power on TV should be no picture with sound again. Grab a flash light or cell phone flash light works just fine.
With TV on hit the menu button on TV remote or the menu button on the TV and flash the light on the screen. Do you see the TV’s menu when you flash the light on screen?
If you do chances are you have some backlights blown out if you don’t see the TV menu you may have a LED driver issue or a Timing issue. ” These are common issues and are not always the cause”

Backlight replacement requires a complete breakdown of the television and requires moderate skill to repair. Mostly due to the LCD panel being so delicate if you crack this the TV is no longer affordable or worth repairing. Even cracking a tiny edge off will render the panel useless.

The LED backlights can be purchased in strips or if you have the skill and tools you can individually repair each LED on the strip.
How many LED’s are in a TV depends on type and size. There is full array lighting which is where the LEDs are from top to bottom. Edge lit LED TV’s is when the LED’s are only around the edge of the television and the light disperses across the panel to illuminate the center of the LCD panel.
There is also CCFL back lighting this was used mostly before LED became the next thing.
CCFL= Cold Cathode Fluorescent Lighting. These can also be replaced. I actually prefer CCFL it’s much brighter and with the right technology blacks can be almost as good as LED based televisions.

This is the TV forced on here

I did not see anything wrong with picture at this point. ” Looking at the picture now I can see one of the LEDs out on the  R1 strip.”
After testing it appeared that the Timing board was the issue it wasn’t it also had a bad LED on Strip R1.
looks like it caught fire!
I did not buy this TV I also do not have the right heating tools to replace individual LEDs.
there are 2 strips in each row total of 12 strips.
1 Strip costs $14.95 plus shipping the TV is 100% apart 1 light is bad chances are more will follow may as well replace them all.
can get all 12 strips for $64.95 plus shipping @  https://www.shopjimmy.com/
First order and get the replacement LED strips. Then carefully pull up old LED strips.

The LED strips new in package.

I used a small thin pocket knife to go under the strips and slowly pry up the strips.
make sure to disconnect the 1st strip after loosening and continue down until you get to the LED power connector board carefully pry and remove.

Add the new lights and place the cover and the lock picks.

Once that is complete then add the panels that go between the LEDs and the LCD panel.
These panels must stay in order so make sure you remove them together and replace them all together.
After these panels are added then place the plastic edge that locks the covers in place this clips on no screws are on this bezel.
Once you lock the 1st bezel down you then place the LCD panel on and add the metal casing that locks the LCD panel in place this will have screws be very careful not to force them on if you even crack a small piece of the LCD panel it’s all over. May as well just scrap it for parts.
Wear plastic gloves when handling the LCD panel if you do not have these then use micro fiber towels to handle it. Once the LCD panel is locked in place you should clean the screen.
Always use water ton a microfiber cloth to clean the screen also a microfiber to dry.
If screen is really bad and from a smokers home like this one was you can use Screen Clean it is ammonia & alcohol free.
As you can see this needed the screen clean.
Was nicotine stained badly when I tried using just water it actually got worse.
Had to use the screen clean agent on this one. Keep in mind smoking in your home cuts a lot of life off of today electronics. They are much more sensitive than the TV’s from the 70s’ -90s’.

Now that the screen is cleaned it’s time to connect the panel back to the timing board and verify that the TV is working.
If it powers on then turn it off unplug and pop the last plastic bezel on front of TV. Flip it over make sure nothing is under TV that can crack the screen and verify speakers are plugged in as well as other wires are in place and taped down.
Left side board-Mainboard  Center brown board-LCD Driver & Power supply Top covered with metal plate -Timing control board.

Once all wires are verified put the back of TV on and screw down and lastly install the stand.

Turn on and enjoy your under $100  50″ HDTV:-)
First time on TV is at default picture values. Set at ECO.

The LG 50LN5400 is not a smart TV it’s just a standard 480i/p, 720p, 1080i/p 24hz/60hz with 120 Refresh.