Repairing LCD monitors at home

From time to time I acquire “dead” LCD monitors. If you start monitor and see normal image and some horizontal or vertical line (black or color) this means that monitor is really dead. In very rare case you can press the LCD module and make the line disappear… But the line means that there is problem in very delicate part of LCD module. But if your monitor is not showing at all, or you see static pattern you have the chance. In fact about 80% of these monitors are repairable.

To begin repairing the LCD monitor you must have some soldering skills. Some spare LCD modules and some spare LCD controllers. These are used to test you new acquired LCD monitor modules. The LCD module can be broken (if have on with crack in the matrix), the only use of that part is to check if monitor is working. Also you must have spare modules for different sizes- 15″ and 17″ modules are not swappable. Also you need hacked back-light lamp generator to check that nice tube lamps.

If you see static pattern and LCD controller is OK, you must open the “non repairable” LCD module. You’ll find very few details. And secondary power supply- check them. Also check for missing parts. Also, with multimeter test the capacitors, resistors and etc. Look for open and short circuit. Also, good practice, is to examine the assembling. Sometime some tiny wire of flexible PCB jumps from its place.

The next image shows 17″ LCD module “Chungwa” CLAA170CE (or LM170E01 from LG Philips, LTM170??? from Samsung). In fact, don’t care who ever made LCD module. You can swap them! I’ve tested Philips modules with Samsung monitor controllers and vice versa. The LCD monitor controller ARE THE SAME. They differ only by software (firmware).

This monitor was not working at all. Few dull line and nothing. I disassembled it for spare parts. But before tearing it apart, I decided to play with it. At it began working. Maybe there was some bad contact in assembly or something. Another problem of this model- the back-light lamp connectors. And lamps were very worn out. So I soldered new lamps. (In other models the lamps are changeable, just remove 2 screws and pull out the lamps).

Now assembled the monitor without the case (I don’t have it!). That small PCB is the controller, and that strange white thing is power supply wrapped to isolating film. (230V lethal voltage!).

The next stage will be to find any suitable 17″ monitor case…