Common cause of LCD TV failure and how to fix it

In this guide I will be talking about the most probable cause of sudden failure of LCD TVs (Samsung, LG etc.)

You may have experienced a situation where your LCD TV that was working earlier just suddenly develops a fault and won’t turn on anymore, maybe due to electrical surge or some other cause.

It has been discovered that the common cause of this sudden failure with most LCD TVs is linked to the power supply circuit.

Nine out of ten of this failure is caused by a leaking or defective capacitor, which is usually identified by a bulging appearance on the top of the capacitors as shown in the image below

Bulged out capacitors

This issue can be fixed by replacing all the bulged out capacitors with new ones having the same values (Capacitance and voltage)

Things to Note: If you are not comfortable repairing things yourself, consult a technician to have it done for you.

To avoid risk of electric shock make sure you unplug any electronics from the power outlet before working on them.

Before carrying out a repair, check the service manual included with the electronics or check online for service manuals for that particular model from manufactures websites or other third party websites.


HOW TO GO ABOUT THE REPAIR

After making up your mind that you are capable of carrying this repair yourself, follow these steps below:

1. Find a flat surface with a wide area like a table and place a soft material, preferably a soft cloth on the surface.

2. Place the LCD TV (screen facing down) on the soft cloth; this is to avoid scratching the screen.

3. Remove the screws holding the casing together from the back of the LCD TV.

Caution! LCD TVs have inverters which can hold an incredible amount of charge, so care should be taken not to touch the inverter as it can result to electric shock.

Also care should be taken when handling the circuit board to avoid damage of components by electrostatic discharge.

4. Sometimes you may need to take off some sort of metal (aluminum) framework in order to expose one or more the circuit board of the LCD TV in some models.

5. Once the power supply circuit is visible, unplug any connectors or cables connected to the power supply board and make sure you take note of their positions for easy reconnection.

LCD TV circuit

6. Undo the screws holding the power supply boards to the interior to enable you work on the board outside the casing.

Now take note of all the bulged capacitors, you can make a mark on each with a coloured pen.

7. Unsolder all the bulged capacitors with your desoldering tool.

8. Get a replacement for the capacitors from an electronic component dealer. You could take the samples along in order to get an exact replacement having same values (capacitance and voltage).

9. Once the right replacement is available, solder them back in place.

Note: when working with soldering iron, take caution not to get it in contact with wires, components or plastic materials and avoid burning out circuit paths by placing the soldering iron on them for a long time.

10. Now put the LCD TV back together in the same way you took it apart, noting the right positions where screws and connectors fit.

Disclaimer: This guide is meant to share knowledge about a possible LCD TV remedy, it does not provide solutions to all LCD TV issues. So I will not be held responsible for any damage to your LCD TV or physical injury resulting from following the steps in this guide. So you must be familiar with electronics in order to carry out this self-repair. And know that working on your electronics will void its warranty if it still within the warranty period.

Hope this post was helpful?  You can ask questions and add your contributions via comments.