LCD Monitor Parts and Repair

Techspirited Staff Oct 23, 2018
Repairing an LCD monitor is a bit difficult. However, for those of you who would like to take it as a DIY task, here is some information on solving some of the basic problems that an LCD monitor faces.
Learning the parts of an LCD monitor and repairing them, if needed, requires that you have some knowledge or expertise in handling electronic components. Below, first learn about the basic parts of an LCD monitor and then, some common issues that affect such monitors and how to handle them.

LCD Monitor Parts

The list of parts can get really exhaustive. Just talking about transistors or other electronic components behind the thin screen, is not sufficient. Besides, component arrangements and specifications within LCD monitors, vary with different vendors. So let us just deal with those parts of an LCD, which are prone to problems.
Opening the LCD monitor's backshell is not difficult, but the problem lies in the fact, that this process varies with the type of manufacturer. Look closely at the monitor and study its external structure before getting into its parts.
You may find some style clips along the outer edges and a few screws at the bottom of the monitor stand. You need to remove them to open the monitor. Inside, you will find a power supply PCB and a lot of electrolytic capacitors, which are the source of most issues and problems in LCD monitors. Externally, VGA connectors and DVI connectors are present.

Issues with LCD Monitors

Stuck Pixels

Stuck pixels are one of the most common problems (and one of the most annoying) in LCD monitors. Liquid Crystal Displays have a simple working mechanism. The backlight in the monitor energizes the liquid in the display, which spreads to all the pixels in the screen.
A stuck pixel is created when the liquid in that particular pixel has not been sufficiently energized. Fortunately repairing stuck pixels is quite simple and you can solve the problem in a few steps. This does not mean you have to open the LCD's back lid and face a number of electronic parts to fix this issue.
Steps to fix stuck pixels on your LCD screen, include:
  • Simply use a blunt pencil to press the stuck pixel.
  • Apply some pressure, but do it carefully.
  • Excess pressure may puncture your LCD screen or may leave a large scratch on it, instead of repairing it.
  • Remove the pencil after a few minutes.
  • Do it for a considerable period of time, until you see that the stuck pixel is back to its normal form.
  • Alternately, you can also run pixel-fixing software. The software turns your monitor on and off at a rapid rate, energizing the stuck pixels.

Rippling Patterns

This LCD issue is complicated and may require professional help, as there are some electronic components that need to be identified. Do not try to solve it yourself, unless you feel you will be able to complete the entire task.
Steps:
  • Open the monitor's backshell and check the components that lie in front of you.
  • Take care that you do damage the front panel of the LCD monitor.
  • Once you have the monitor opened, check if the power supply is working properly.
  • The power supply and the control circuit will be hidden under a metal cover.
  • Remove the screws and open the cover. You also need to screw out the leads of the backlight power, the IEC power receptacle, VGA connector, and DVI connector.
  • Once you are done with the components, you will find a lot of capacitors.
  • If any capacitor is poking out, test it using an LCR meter. If it shows zero capacitance, then this is the problem. But it may not just be limited to one capacitor.
  • Locate all the capacitors that look faulty or bulging out and check them with an LCR meter.
  • Capacitors are relatively cheap and you can replace the faulty capacitors, with capacitors of the same specification.
  • Keep in mind that if you have detected a capacitor of 470 micro Farad/25 Volt with 0 capacitance, it needs to be replaced by a capacitor with the same specification.
  • Fix back all the components carefully and close the LCD monitor backshell. Turn on the monitor and check if the problem is solved.
There are a wide array of other problems which may arise in your LCD monitor and many of them can be solved using the above steps. 
For example, if you find a horizontal or vertical line of dead pixels on your monitor's screen, then you can try the method for energizing the stuck pixels. If repairing the monitor seems a daunting task or you are unsure of electronic parts and components, leave the repairing to the experts. 
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