If you have a Samsung SyncMaster 204B monitor that either has a blinking power light or a very dark picture then this should help get you back running. There are 2 different versions of the power supply board and you will need to check your version before ordering. The monitor dis-assembly is the same for both versions of board. You can check the capacitors in the center of the board, if they are 680uf then this is the correct kit, if they are 330uf then use the 214T parts kit available here.

Below you will find a full walk thru on repairing your LCD monitor. To do the repair you will need the following tools: Soldering iron, de-solder braid, Phillips screwdriver, flat blade screwdriver. You will also need the following electronic parts: Qty(2) 680uf 25v, qty(2) 820uf 25v capacitors, qty(1) 330uf 25v. We sell a repair kit with all of the parts for $12.00

If you don’t want to do the repair yourself, use the service request link above. Most monitor repairs run $30-35 plus return shipping.

Here we have a non functional Samsung SyncMaster 204B 20″ LCD monitor. This unit has a fast blinking power light. We have repaired several of these in our shop and they all have the exact same issue with the power supply.First you need to remove the power cable, signal cable and the stand. To remove the stand you will need to remove the 2 thumbscrews, they are circled in yellow.Once the base is removed you can easily remove the VGA or DVI signal cable and power cord. When working with a flat panel display it is best to put a towel down on your work space so you don’t scratch the front of the display.To remove the cover you will need to use the small flat blade screwdriver. Across the bottom there are several release tabs, if you insert the screwdriver into the slot the case will release. When you get one corner released just work your way around.

After the screen unit is removed from the plastic case we can get down to the repair. We need to remove the power supply unit. You will need to unplug the control panel, circled in red. The remove the 6 screws that are holding the metal shield in place (yellow circles).Now unscrew and remove the power supply board. To remove the board you need to unscrew the 5 screws circled to yellow and unplug the 2 backlight plugs and the signal cable, all circled in red.The 5 capacitors that need to be replaced are circled in yellow. We have already replaced the capacitors in this picture. Before replacement all of these caps had very noticeable bulging tops.
The replacements are as follows:
C301 and C302 680uf 25v – yellow circles
C111 and C110 820uf 25v – red circles
C112 330uf 25v – blue circle
Be sure to reinstall the caps with the polarity stripe going the same direction as the old ones come out. After the parts are replaced just reverse the procedure to reassemble the case. Now apply power and you should have a fully functional monitor again.

9 Comments on Samsung 204B LCD Monitor Repair

Mike on Sat, 1st May 2010 11:39 am


Thanks loads for this.
Saves me buying a new monitor.

Laz on Sun, 6th Jun 2010 10:20 pm


the only really hard part was opening the case; I found that firmly running an expired credit card in the seam along the long side of the case allowed the snaps to clear so the front part could lift off. I had to run the card all the way around before the two parts could be separated without breaking or damaging anything.

Sharma on Thu, 26th Aug 2010 10:45 am


Is this the problem also when the monitor takes some time to come to full brightness ?

admin on Wed, 8th Sep 2010 8:51 pm


Yes, The slow brightness is because the power supply board is taking a long time to get to full output voltage. The kit we have should get you back to full brightness in no time. You can get it here: http://www.ccl-la.com/catalog/product_info.php?cPath=21_33&products_id=35

Justin on Mon, 13th Sep 2010 8:44 am


I was having this same problem so I ordered and installed the caps. Now all I get is a white screen. Did I do something wrong or did a different component now fail? Thanks for any suggestions.

admin on Tue, 14th Sep 2010 7:56 pm


Check the cable from the the video board to the display panel – its the flat cable about 1.5″ wide. If this cable is no connected securely then it will cause a white display.

yuri on Sat, 16th Oct 2010 1:40 pm


I am thinking about fixing the 204B as I have a slow (1-2min) and flickering start. However, I also have a pixel-thin line left to right at the bottom of the screen – will this repair fix it?

CCL_TECH on Mon, 18th Oct 2010 1:14 pm


The thin pixel line is not caused by a power issue, its caused by a faulty driver transistor on the LCD panel. This type of fault is not correctable except by swapping the panel out which is expensive.

peregrine48 on Fri, 17th Jun 2011 2:22 pm


Wow, Thanks Guys!

This was my first real attempt at soldering.

$12 to fix what was originally a couple hundred dollar monitor that I really liked.

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