LG 47LN5400 – 47 Inch Television No Power Troubleshooting

I received an LG 47LN5400 television for recycling. This television would NOT power on. I tried pressing and holding the power button for 30 seconds.

This did NOT fix the problem. I decided to then take off the back cover. You will need to remove 23 total screws.

Also, you need to remove the television stand. There are some screws hidden behind the television stand. Once you remove the screws you will be able to easily remove the back cover.

This LG 47LN5400 is quite lightweight and has very few circuit boards compared to other televisions I have worked on. I disconnected all cables from both power, inverter, and video boards. I then reconnected all these cables.

When I went to power on this LED television there was no indication it was receiving power. I noticed two missing screws on the power board. I found some comparable screws.

Perhaps this television was serviced before? Who knows, I do NOT know. However, this did not fix the problem.

I was NOT able to get this television to power on. I will need to perform further research and see if I can salvage this television. The owner claimed that this television would not power on.

They did NOT say that the LED screen was damaged or not functional. However, I do NOT necessarily want to order replacement boards if this television has a malfunctioning screen. Speaking of circuit boards, there are only four boards in this LG 47LN5400 led television.

* main power board
* inverter board
* video board
* manual controls board

I am suspicious that perhaps the power board is the culprit. I will need to test for failed circuit(s) with a multimeter. If I can fix the power board by soldering any failing circuits then I can sell the television.

I do NOT repair televisions on a daily basis. If I have deduced that the power board is the failing component, then I might order a replacement board if they are not too expensive, if I cannot repair the power board myself. On a final note the owner left me the original power cable, remote control, and manual for this television.

It is in excellent condition. I would hate to part it out, but at least if I do, I can sell the boards or make sure that it does NOT just end up in a landfill.