Tip & How-To about Computers & Internet

Fix my Dead LCD Monitor

LCD monitors use a special power supply called a Switching Power supply. Due to the stress these put on the parts inside, the parts called capacitors wear out.
It is a fairly easy job to open a monitor (Power off, eh?). Carefully unscrew the board that has the power cable connected to it. Each of the parts marked C101, C102 etc or similar, is a capacitor.
On the side of the capacitor are some values EG: 1000uF/16V or 470uF 25v or 2200uF 10v. Each of these parts has a special job to do in the monitor. The larger the value, the more likely it fails.
I simply replace them all.
BE VERY CAREFUL in the area of the large capacitor labeled 180uF 200v! (Or similar) This may have a charge on it. I unplug a working desk lamp and place the prongs of the plug across this capacitor before I do ANYTHING. Safety first, eh?

This is a picture of a Dell monitor Power Supply. The black cylinders are the capacitors.
Take care and good luck. I have fixed HUNDREDS of monitors this way.

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i have bad 680uf 16v capacitor can i replace it with 1000uf 16v capacitor


The 1000uf is to far out of tolerance to work correctly. You also need to be sure that the capacitors you use are rated correctly for use in high speed switching power supplies. The parts will need to be low ESR, high temp and high ripple current. replacement parts from places like Radio Shack or Fry's will not work right and could damage your power supply board. Here is a link to a page that explains more about getting the correct capacitors for this type of repair.


You should also charge all of the capacitors on the power supply board because when one shorts out it put a stress and the others and they will start to fail soon too. Replace them all while you are there so you don't have to reopen the case in a month and replace the rest.

Sep 08, 2012 | Hanns.G Corporation HW173D Monitor

1 Answer

acer monitors bad caps

Your not using the correct ratings on the replacement caps. The replacements neewd to be low ESR, high ripple current and high temp because the switching power supplies put a lot of stress on the power supply parts. The Acer units just stress the caps a little faster than other models. Any other brands that you have repaired with these parts that are not to spec will fail within a few months and could damage the power supply board when they do. Here is a link to more information about getting the correct capacitors for monitor power supply repairs.


The link article shows brands and series that have the correct rating for this use.

Jun 20, 2012 | Acer AL1917 LCD Monitor

1 Answer



Slow displaying displays is a common symptom of a failing power supply board. Parts called capacitors will start failing which causes the power supply to not stabilize the voltage and power the monitor. The monitor power board keeps resetting and trying and finally it will stabilize and you get a picture. If you checkout this article on our web site: http://www.ccl-la.com/blog/index.php/capacitors/ this will give you information about what needs to be replaced with pictures and specifications. The repair will require soldering the new parts onto the power supply board. If you do not want to do the repair yourself we do offer a repair service, most repairs run $30-35 plus shipping. Information can be found here: http://www.ccl-la.com/blog/index.php/service-request-form/

I hope this helps, if so please rate our solution.

Corporate Computer

Apr 25, 2010 | Samsung SyncMaster 740N 17" LCD Monitor

1 Answer

Monitor keeps switching itself off

You may have failing power supply.
Most common failure in the LCD monitors are bad capacitors (bulging top/seal or leaking) in the power supply, failed inverter circuits (blown fuse, shorted transistors, shorted/open transformers), bad lamps (poor solder connections or worn out lamps). You will need to open it up and inspect the inside, see example of failed monitors to get some ideas of what goes wrong: http://s807.photobucket.com/home/budm/allalbums
Post back what you see inside so we can guide you further, it will also help out other people with the same problem.


Apr 05, 2010 | HP Compaq FP 7317 17" Flat Panel LCD...

1 Answer

monitor screen looks dark but if you look close you can see image

husslin, Yes, you too can join the crowd of people whoose LCD/FPD power supply and or Cold-Cathode-Fluorescent-Tube power supply(called an INVERTER circuit) which supplys hi voltage to light up the backlight tubes so you can see all the pretty colors on the front of your screen has failed.
If Samsung won't do a swapout, you send them your's plus some cash and they send you a same model refurbished unit in exchange, then most likely you will need to effect a repair on your own. The fact that you are able to see the image ( Windows Desktop or IE) is a good sign. It means that the MAIN POWER SUPPLY board is at least supplying voltage to the logic/video processor board inside the monitor. LCD/FPD displays have 2 or 3 printed circuit boards, not counting the tiny board that has the on/off and adjustment switches on it. The large board that is connected to the AC line will be the Switch-Mode-Power-Supply which may or may not include an on-board Inverter circuit. These SMPS/INVERTERs have 2 causes for failing. Either one or a combination of the two. Failed ELECTROLYTIC FILTER CAPACITORS from thermal stress, and or other heavy components whoose leads are soldered on the bottom of the board have developed circular stress cracks in their solder joints. Well, I've probably told you enough to get both of us in trouble, but if you surf over to youtube, do search for vids on lcd monitor repair and or bad capacitors or swollen caps in lcd monitors. Got to run now, but you can get back to me at louie12fix on fixya or lmistyrel@ aol.com
PS look for vids on lcd dissaembly or such. I have seen some about 10min long.

Apr 01, 2009 | Samsung SyncMaster 920NW Monitor

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