Monday, April 15, 2013

How to fix an lcd monitor

The story:

One lcd monitor that is not showing anything but the power led is on. By removing the cable from the source (video card) normally on the screen there must be a warning that there is no video source connected.

If you are disconnecting  the cable from the video card and you have an adaptor on the cable you should remove that adaptor. From experience i know that if you have an vga-dvi adaptor on the cable that warning regarding the video source is not showed.

The cause:

When the power led is on but on the screen you don't have anything usually the problem is bad capacitor or a fuse.

Lets see what i need to fix this monitor:

First step is to remove the plastic casing of the monitor and for this task i use two screwdrivers: one flat and one philips. With the philips screwdriver i remove the leg of the monitor, usually there are 4 screws. After that i can use the flat screwdriver to unclip the clips that are holding the two parts of the casing (front and back).
The next step is to remove the sheet metal that is covering the boards - this can be different for you because that sheet metal can be bolted or clamped-  in my case there are clips.
After removing that sheet metal i brush the dust and take a look at the boards - bad capacitors.

Replacing capacitors:

For this task i'll use my soldering station , solder, solder pump and small pliers to cut the leads from the new capacitors.
So... the first step is to remove the board by disconnecting the cable, screws.
I add solder to the joint and with the pump i remove all the solder with the press of one button.
Next step is to insert the new capacitors on the board and solder them in place after that i can trim the leads from the capacitors.

The moment of truth:
After assembly of the monitor is done it time to power it up: the warning that no video source is connected now is displayed on the screen.

Thank you for your attention.

No comments:

Post a Comment