Repair of a Samsung 204b LCD monitor

The Samsung 204b has been a great monitor for me for years.  Recently, it has started to take longer to “warm up” before displaying anything.  It got to the point where I would turn it on, or move the mouse to wake it up, and then wait up to a minute or longer before anything showed up on the screen.  Finally, yesterday, it just stopped displaying anything.  The indicator light that signals power was on, but nothing was displaying on the screen.  It was time for a repair.

The first thing I did was google “samsung 204b repair” and I came across this website:

http://pavel.kirkovsky.com/2009/03/samsung-syncmaster-204b-repair/

Among other things, it showed me that CapXon capacitors on the power supply board were the most likely fault, repair was possible and pointed to a mouser cart that already contained the necessary parts.  As it turned out, I only needed to replace the two bad capacitors that are endemic to this brand of monitor: C110 and C111.

I feel I should add this warning.  Capacitors can be dangerous, and in some cases even deadly.  Please use caution when working with circuits and understand what capacitors are and how to discharge them safely before continuing.  I am not responsible for what you do based on this blog post you found randomly on the internet 🙂

Read on for a step by step guide to repair the Samsung 204b.

I don’t want to get rid of this monitor, imagine having to track down all those decals again for the new one!

Front view, sorry about the blur.

The first step is to jam a screwdriver into the crack near the buttons and try to find out where the plastic tabs are that keep the monitor together.

Clearly the tabs are on the bigger side, so I have to pry in this direction.

As I pop a tab, I continue down the side of the monitor until the whole bezel is loose.  Some of the tabs break, but that won’t keep the monitor from staying together later.  If you want to be really careful, there are tools that facilitate this process.  I only used a common screwdriver.

This is a two-handed job.  One hand holds the bezel, the other takes a picture.

The buttons are connected by a thin wire, which can be disconnected from the main body after I remove the back section of plastic.

And here it is without the front or back case.  There are six screws to remove.  Two on each side and two on the upper left seen here.

Do not lift here! Instead, lift from the corners. I made this mistake while taking the picture before I realized I was lifting the whole circuit board instead of just the frame.  The frame can be lifted off by itself.

Aha!  You can see that the two caps in the middle of the picture are swelling from the top.  This is a clear indication that they are bad according to the website.
http://pavel.kirkovsky.com/2009/03/samsung-syncmaster-204b-repair/
In my monitor, only these two caps were bad, lucky for me.

The caps are numbered C110 and C111.

The board must still be liberated from its case by detaching two cables on the right and one on the left, unscrewing four screws, and gently lifting the board out of the case.  Then, set the case aside and get ready for some soldering. Be careful not to touch the capacitor leads until you have discharged them (see http://www.repairfaq.org/sam/captest.htm).

Here are the target caps, C110 and C111 from the back of the board.  My mission is to desolder these four connections, bend the pins back, and remove the caps.

Done, and new caps soldered in place. You can see the new ones I bought were too big for the space, but still fit nicely with all the room around them.
The original caps were rated 820μF, 25V.  The new ones are 820μF, 50V, which I read was fine as long as it’s rated above the voltage you plan to use.

I laid one of the caps flat against the board.  There was lots of room and positioning it this way prevents any kind of problem closing the case.  I didn’t have a lot of clearance above it.  Just make sure none of your leads will touch anything metallic, or there will be problems.

With the caps in place, I put the board back in its spot, plugged in the cables (3 on the power board, plus one attached to the bezel for the buttons) and put the monitor back together.  Now comes the true test.  Will it work?

Success!  The whole project took about an hour and a half for me, and I have no experience with this particular monitor.  A very easy fix for someone who is careful, dedicated, and knows how to solder.

Hope you find this informative.

26 Replies to “Repair of a Samsung 204b LCD monitor”

  1. Thank you very much for step by step guide. I have same monitor as you have and I dont even know how to open the case before I found this site. Five of my caps are bad and needed to be excanged. I will bookmark this site

    Excuse my bad english 🙂

    /Tord

  2. I have a Syncmaster 2253LW screen. The symptoms described in this site started about a year after I purchased it at Costco. It was too late to return it. So I started hitting it as it would get flakey. I found where it would be affected the most (both sides about a third of the way down) and after about 4 well placed hits it would work. My son discovered that picking it up and turning it upside down would work better than bashing it every morning.
    So, I replaced the caps. It still has lines on the screen and segments of the picture broken up until it warms up. Bashing does still seem to improve the picture. The one thing about this picture is that the resolution seems to be incorrect. It appears that every other horizontal line won’t go dark enough. There are also missing vertical lines every 50 lines or so. I realise that bashing isn’t the best way to treat this box and may have caused these other problems. I would still like to get the monitor working. Any suggestions?

  3. It sure seems like electronics fail right after their warranty expires. But it makes sense, since warranties are like insurance. The company bets their product won’t break within that period of time, and push it back as far as it’s safe to attract buyers.

    It sounds to me like your problem is slightly different than mine. When I turned my monitor on by pressing the button, or moved the mouse after it had gone to sleep, I saw nothing on the screen. Once it “woke up”, however, the picture was perfect and lasted until I turned it off or it went to sleep again.

    Other than Googling the problem, which I assume is how you ended up here, I would suggest trying to determine the exact thing that fixes the problem. Banging on it rattles it up a bit, but turning it upside down causes things to shift, so for example a wire that’s not connected at one end might make a connection when gravity changes it’s position. To me, that indicates that something is loose inside your monitor. You could also check for signs of a short, like burn marks or oxidization. That indicates something is wrong. Finally, you might just want to give up and buy a new monitor if it’s not worth the trouble. I almost did before finding this guide.

  4. I appreciate the suggestions. It’s OK. I have other monitors and will survive. I’m pretty sure that there is no loose wire or any burn marks – I opened up the case and checked for the obvious stuff way earlier in the game. I heard on Newegg that the caps were crummy and that’s what sent me here. Sure, there could still be other defective parts. I know it’s kind of a lost cause. But, I’d like to figure it out anyway. The picture is still OK enough for reading email. I’ll keep searching. I wonder if someone has an old compatible Samsung video board? Maybe if some other part is broken and you’re planning on tossing it, I’d pay some reasonable fee…

  5. Am working in a large institution where we use samsung tft monitors in most of the workstations. The issue of faulty capacitors is very common with this kind of monitors.What may be the cause of this prolem? Please help

  6. The cause of the problem is badly made capacitors from companies in China like Capxon. The idea is to replace them with better quality capacitors. I know it’s a problem with the 204 series since they were cheap monitors. Not sure about others.

  7. Thanks a whole bunch! I replaced 6 of the 7 capacitors(whether they needed it or not) – except for the big one and the monitor came right on. I only broke 2 tabs and there is no noticeable damage to the case after completion. Can you imagine how many people just throw away monitors that have stopped working?! I am so glad I didn’t have to dump this one into a landfill. Thanks again for all the instructions!

  8. Thanks for saving me the cost of a new monitor…appreciate the effort you have put in to the detail here to assist others with what I now understand to be a common problem with this monitor. Mine now working like new also.

  9. Ive had three of these monitors with the same problem for over a year now, but never could get myself to throw them away.
    now after i found this site i have since replaced 5 capaciters from each of them and they are all now up and running with a renewed purpose.

    Thanks you.

  10. It’s good to see how many people have been helped by this post. Thanks for adding your experience too.

  11. Thanks for the great post! The case came apart beautifully using a putty knife without a single broken tab. After $5.56 and about 1 hour of work the monitor works perfectly! My local Fry’s did not have the right values. Radio Shack stocks a 35V 1000uF (instead of 820) and 35V 470 uF that work fine. I like the idea of using a higher voltage capacitor considering the old ones failed. Since the caps are slightly wider, I also laid one of the capacitors on its side and secured it with a little shoe goo.

  12. Thanks a lot for advices, I replaced 4 Caps and now my Monitor works again 🙂

  13. Hello,

    I have a SAMSUNG Sync Master 204B over four years. The monitor got a display problem. 2/3 display area is brighter than rest area. Are there replace CAPs to solve this issue?

    Thanks,

    Key

  14. My guess, as an amateur who knows very little about how LCD components work together, is that this has nothing to do with the power board.

    My second guess is that maybe you have a short somewhere from your fix.

    Since that is most likely the last thing to have changed, I would explore there first. Unfortunately, if you can’t find the problem, or find it on google, or know an expert, there’s very little you can do.

  15. Thanks for the website. I replaced the two capacitors c110 and c111 that I bought from Mouser Electronics and the monitor works like new now.

  16. I can just copy what Hurley said exactly, so I will:

    Thanks for the website. I replaced the two capacitors c110 and c111 that I bought from Mouser Electronics and the monitor works like new now.

    I bought all the capacitors in this cart since they aren’t too expensive https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=ec01c39999
    but the C110 and C111 were bulging and it wasn’t too difficult to take apart, so I decided to try those first and everything works great. Thanks again.

  17. I did the same thing, based on the reference article I used, I just bought all the capacitors in the mouser cart. But I also only had to replace the two, and my monitor is still working. I also showed this post to a coworker and we fixed one of his Samsung monitors the same way.

  18. I replaced c110 and c111 today with the same component. Fat capacitors, had to lay one on its side. It’s working again (no more flicker or black screen)! One thing I noticed is that now my monitor takes about 1-2 extra seconds to turn on, but it is consistent, at least.

    Easy fix.

  19. I recently bought my 204B used from work (five years old for USD63) and was very glad to find this thorough instruction.

    In my case the two C110 and C111 820 uF capacitors made by CapXon were a bit bulgy on top and after removal I measured them to only 270 uF. I replaced them with 1000 uF.

    I also replaced the three 330 uF made by Samxon. But it was probably unnecessary since I measured them to exactly 330 uF after removal.

    (Material for about USD4.)

    At the same time a drilled several extra holes in the plastic rear cover to improve cooling when used in portrait position.

  20. Just completed this fix, thanks a bunch. Comments were great as well. Picked up two 1000uf 35v capacitors ($3 – only two were bulging) from Radio Shack, as well as a $10 soldering starter kit that came with a 30w soldering iron, solder (contained iron) and a crappy little stand and two useless tools, and a $4 spool of desoldering braid. My first real soldering job, and it took me about an hour to desolder and solder the four pins (total for the two capacitors). Started up without a hitch, hopefully it will be good for a long time. $17+tax to get my monitor back! Thanks!!!

  21. A great site. Gives me all the confidence to have a go at my two great 204B monitors. They seem to be aging (dimming, like my wits). I will replace most of the aluminium caps on the High Voltage board (my boards are rev. 0.1); that is, C110+111, C112+C304+C305, C107 and for good measure the fat C105 CapXon cap too while I am at it. By the way, the board identifies the caps by number, so have no worry not being able to identify them. See also article by Jcwren on the repair (google it) and google YouTube for the repair. Good luck, and thanks Pavel. Greetings from the South Pacific.

  22. I doubt anyone on this forum would want to do that. And even if so, the shipping cost exceeds the value of the repair, especially when you factor in the possibility that the capacitors aren’t the cause of the problem you are experiencing.

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