A friend of mine recently gave me his malfunctioning Samsung SyncMaster 204B monitor. He reported problems with display flicker and intermittent failure of the backlight. Suspecting a bad inverter, I plugged it in on my workbench only to be greeted by a blinking power light. Thanks to some Google searches and a hint from this page about the slightly different 204T model, I started to suspect bad capacitors.
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This project deals with high voltages and can be lethal! Proceed at your own risk. |
THE PROBLEM:
On this monitor, the power supply and inverter boards are integrated into one unit. There were bulging capacitors all over the board:
All but 2 capacitors were affected, but I am going to replace all of them. The manufacturer is CapXon (aka CrapXon), which is a Chinese manufacturer with a less-than-stellar track record.
| Capacitor | Value | Comment |
|---|---|---|
| C112, C304, C305 | 25v/330μF | C304 looked okay, but I’m going to replace it anyway |
| C110, C111 | 25v/820μF (replacing with higher capacity is OK but it must be rated at least 25v!) | Both of these are bulging badly. C111 is starting to leak |
| C105 | 450v/100μF | This is a filter cap for the power supply. Looks fine, but still made by CapXon |
| C107 | 50v/47μF | This cap also looks fine, but it’s a very common value and cheap to replace |
THE SOLUTION:
The site hosting the 204T PDF seems to be a little slow, so I have mirrored it here. Keep in mind that the board shown in this PDF is somewhat different than the board in a 204B monitor, but the disassembly instructions are identical and very helpful. Here is the power/inverter board of the 204B monitor, with arrows indicating which capacitors need to be replaced:
Here is a Mouser.com saved cart of all the parts you’ll need. Last time I checked, it would cost about $5, plus shipping (which is ~$7 for me) for all the capacitors on the power supply board (the ones listed above).
The saved Mouser cart has now been abandoned. See the “caveats” section below…
CAVEATS:
Sometimes the parts in the Mouser cart may be backordered.
You can try searching for in-stock parts that meet the proper specs:
- Go to the capacitor search
- From there, use the table above to choose the capacitance. Click “Apply Filters” to get the results.
- Pick a voltage rating that meets or exceeds the voltage in the table above. Click “Apply Filters” again.
- Sort by price (cheapest first), then picking a Nichicon/Xicon/Vishay/United Chemi-Con/Panasonic cap.
| Don’t forget to look at the physical dimensions! Some of the listed capacitors may be too tall to fit in the monitor, so double check by clicking on the product ID and verifying the length (L). |
If you’d like to use another site such as DigiKey, make sure that the capacitors you choose are aluminum electrolytic, through-hole, and radial lead.
DigiKey and Mouser mostly cater to North American customers. If you’re located elsewhere, try Farnell or RS Components.
Beware of Chinese caps!
This is so great. I’m using my newly revived monitor right now. I really glad you elaborated on the YouTube post as you pretty much answered any question that would come up. Especially issues with the new caps fitting. My 820 caps were to tall but I just leaned them over a bit and it works fine. All my caps were bulging except the little one and i replaces all of them. before it took about half an hour to see anything on the screen, now it is instant. Thank you Thank you Thank you.
Thanks for the guide! I have also been experiencing the flickering issue for the past few weeks. I took my monitor apart and also found that C110 and C111 were both swollen…not leaking yet. I stopped by the local Radio Shack and was able to get all the needed parts to do the repair. My monitor is now working perfectly!! Thanks so much for this info! Just before finding this site I was shopping on NewEgg for a replacement…now I can save money!!
BTW – my LCD case was a little different to take a part. I could not locate the “green tabs” as indicated in the PDF. I started at the back bottom right and began prying on the case until it came apart. I managed to break the little clips in each of the four corners, but I doubt it will have any problems as the stand on the back pretty much holds the load.
Thanks again!
-Andy
Thank You So Much Pavel! $5 and my beloved 204B is like new!
My board is Rev 0.1 with no 680µF caps and a 150µF at C105. All caps are CrapXon except the 330µF’s which are Samxon (Hong Kong). All caps are rated at 105ºC.
I will order a complete Cap replacement set but, since only the 820µF caps at C110,C111 were bulging, I went with the Radio Shack 1000µF 35V caps, pn 292-1032, 85ºC, $1.59 each. At 12.5mm x 20mm, height is perfect but the diameter is a little too wide so one had to be tilted slightly.
Thanks to Nick, a $1 2″ Plastic Putty Knife works perfectly for opening the case. Standing the panel upright, upside down, and holding the knife ‘stabbing’ style, starting over the ‘Samsung’ label, just push down with increasing pressure until the snaps yield. It sounds like they’re breaking but they’re not. Once the first ones open, just slide the knife along the widening gap while still pusing down with a rocking motion. The corners were a bit harder so I didn’t force them, just rotated the panel and started in the middle of the next side.
I used a $.50 10W 10kΩ wirewound resister to discharge all caps. Since the leads were so long, I just bent them at 90º and held the resistor with forceps across all cap leads for a minute each.
Desoldering was no problem at all. Using a Radio Shack 15W/30W soldering iron set to 30W, the old solder melted right away and wicked away easily. The leads were bent over but also seemed to be glued. I gently pried with a small knife at the tip of the lead until it moved then used forceps to bend upright. A slight push with the soldering iron and the old caps fell right out.
The whole operation took just over an hour but I was being anal about not rushing and getting it right.
The results were astounding. Went from a 15 minute wait for a dim image at 100 Brightness to an instant-on blazing image even at 25 Brightness!
Thanks again to Pavel and all who have contributed! It gave me the confidence I could do it myself!
This works. My monitor was taking 5+ minutes to warm up. I used the suggestions here and replaced C110 and C111 with 2 1,000Mf 35v capacitors from Radio Shack for $1.60 a piece. The whole project took about an hour and the monitor works. Thanks for the help.
David
Sorry, wrong abbreviation. Should read” 2-1,000 UF 35V.
Mouser was great
great information thanks
Thanks for the info! I ordered the parts below, not being sure what rev boards I had. I have five of these LCDs, and two were flaky, so I ordered enough to fix all five. Turns out the two I had to fix were Rev 0.0 boards. Some of the caps were swollen, two had actually oozed out the tops.
Hardest part was getting the cases apart. I screwed up the corners on one of them, broke the little internal locking tabs. Some close-up photos would be really good to add.
Of the five LCDs, four are refurbs, one was bought new. The new one and one of the refurbs had to be fixed, and the [removed - please watch your language] at the refurb center apparently thought the four machine screws that hold the back shell on were optional. Luckily, from my large collection of PC case screws, I found four that were correct.
Below is my Digikey list. I used different 47uf caps than the ones Xiachen warned about, the 565-2004-ND’s fit with no issues. The 820uf’s were a little taller than the originals, but still cleared the shell with a couple millimeters to spare.
1 10 565-1553-ND CAP 820UF 25V ELECT KY RAD 0 0.45900 $4.59
2 10 565-1551-ND CAP 680UF 25V ELECT KY RAD 0 0.36900 $3.69
3 10 565-1984-ND CAP 330UF 35V ELECT LXZ RAD 0 0.49200 $4.92
4 15 565-2004-ND CAP 47UF 50V ELECT LXZ RAD 0 0.31500 $4.72
Incidentally, the caps in my boards where made by V O A.
Probably NOT Voice Of America
thank you.
can please someone get me the website i can order capacitors(820uf 25v) really worked, because i don’t wan’t to get defect some chinese. pleaes help. thanks,
How in the world did you remove the old caps? I cranked the soldering gun up to 860F and those suckers didn’t move at all. The solder barely looks dented. Any tips?
Thanks in advance!
-Erik
Erik,
I use a Hakko 808 desoldering gun.
It’s not cost-effective for a one time job, so I’d recommend using liquid flux and a flat-tipped iron.
Thank you so much!
I have a Samsung 204B that takes 5 minutes to light up. I was going to send it to Samsung service center (in NJ?). It’s out of warranty.
Here are the parts that I ordered from digi-key:
Qty Part Number Description Unit Price Extended Price
2 P11221-ND CAP 820UF 25V ELECT FC RADIAL 1.07000 $2.14
3 P12414-ND CAP 330UF 35V ELECT FM RADIAL 0.43000 $1.29
1 493-2074-ND CAP 100UF 450V ELECT PW RADIAL 3.81000 $3.81
2 493-1554-ND CAP 680UF 25V ELECT HE RADIAL 0.66000 $1.32
1 P13464-ND CAP 47UF 50V ELECT EB RADIAL 0.14000 $0.14
The 680 uF cap is only needed for Rev. 0 boards. I was not sure what hw rev. is my 204B. So I ordered it.
Try to order other 47UF 50V caps. The one I ordered has much thicker legs and it wouldn’t fit into the hole on the board. I had to do the drilling.
C110 and C111 on my board obviously look bad. I replaced other caps as well. It took me the whole night to do the job. I am very clumsy.
Now the LCD works fine.
Thank you very much.
One of my 204B takes about 15 minutes to display the screen. Even then it flickers for another 15 minutes before becoming stable. I followed this guide along with the comments posted below, ordered the capacitors (2 sets for 2 LCDs) from Digikey, and replaced just the broken ones. The bad LCD has been fixed.
My new C110 and C110 have diameter larger than the stock ones. Once replaced, they sit at a slight angle to one another. I was more concerned about their height than width.
A note, the OEM capacitors terminals need to be straightened out in order to remove them without too much pulling force.
Total cost of two sets of capacitors: ~$20 (including S&H). I’m back to using dual LCDs. Thanks for the guide!
Thanks for the web-site.
My 204B monitor was very slow coming up and though damm, “I have to buy a new monitor”. It was not a cheap monitor either.
I ordered a set of caps from Digi-Key.
I selected the highest quality caps they had, and it still was under $10 bucks with a few spares.
I used a putty-knife to open the case, which left no scratches. Pushing it in and then twisting it slightly unsnapped the “hooks”. It was very easy.
The replacement went fine, I got some caps that were a little taller so I put one of them at a slight angle for clearance.
I did not replace the 450V/150uF cap, it seems to be good enough (I still have the replacement cap sitting in a drawer).
All original CapXon (CrapXoff?) caps, except the 450V, had bulges. I measured their capacity with a humble Wavetek 27XT DMM: The 820uF caps measured ~120uF, The 330Uf caps measured 100 -130 uF, the all important ESR (which I have not yest measured) is likely degraded too.
The 450V/150uF cap was in spec.
These are the caps I got from Digi-Key:
P11221-ND 820uF/25V $1.07/ea.
P12414-ND 330uF/35V $0.43/ea.
P10321-ND 47uF/50V $0.28/ea.
493-2074-ND 100uF/450V $3.81 (not used)
The monitor now works fine and comes up instantly.
Thanks for posting this. I was having the same problem on my 226BW and there were three bulging caps – C111, C112 & C114 (they are the same ones as your C110 & C111, except the 226BW evidently has 3).
Replaced with Panasonic EEUFK1E821′s (for other UK users, you can get them here: http://uk.rs-online.com/web/0571290.html).
The monitor is easy to dismantle, the PCB is well marked and not too cluttered around the cap pins, so it’s about a 15-20 minute job.
Sorted. Once again, thanks for your help
Worked great! Another happy reader. My 204B did not flicker, it just shut down completely after running a few minutes. Gradually it started shutting down sooner and sooner until I couldn’t even get to my boot prompt.
My 204B’s CapXon capacitors showed no physical damage. They looked like new. I sent away for the Mouser shopping cart posted on this page (fall 2009) and it took two months to arrive. The caps physical size was a problem in a few cases, but fortunately I was able to bend the leads a little and fit them all in.
My 204B also had the problem with the DVI input at 1600×1200. I don’t know if it still has it or not – I just use the VGA now.
Note: I just noticed they are selling sets of replacement caps on e-bay. About $11 inclusive.
Very useful information. I was able to fix my Samsung 204B by replacing those capacitors. Works perfectly now!
Now all that remains is to fix my other 204B that suffers from the same problem.
Thanks
1. What’s the trick to getting the bezel and back separated?
2. Do you really have to discharge the capacitors before removing? Any place to actually get a capacitor discharge line without having to construct one – or a different way of discharging them?
3. Any other important tips or hints to get this done right? Not a electronic engineer here.
Thanks!
Be sure you are familiar with a soldering gun and know how to remove the existing solder with a braid.
If you are not good at this, you should probably get a friend to help you.
Hi Dana,
The “trick” is to simply pry at the case with a tool that won’t mar the case. Plastic putty knives are preferred, but you can also use a plastic card, disposable chopsticks, or a CD (I prefer the clear dummy discs from CD-R spindles).
It’s highly recommended that the capacitors are discharged since it’s very easy to give yourself a nasty jolt. Don’t short the terminals with a metal object since this might lead to a small explosion. All you really need is the power resistor – the alligator clips and insulated wire are to make things safer. I don’t recommend this since the leads are exposed and the resistor may get hot.
The whole procedure is pretty straightforward. To save yourself extra work, look carefully at both sides of the board and make sure there are no damaged components, scorch marks, or other anomalies. If so, the board has some other problem besides the caps.
Something not mentioned here, some SyncMaster 204B intermittently go blank because the DVI controller Samsung used to build this particular model is at the edge of it’s controller bandwidth when operating at 1600x1200x60Hz. (VGA doesn’t run into this problem because it uses a different controller).
So, to diagnose – use the VGA controller — if you still have blanking issues it’s probably a hardware problem as described above; if this resolves your problem, chances are you need to tweak your video card timings to work with this monitor. I found just forcing 1600x1200x59hz worked well, but I saw several articles on the Internet that claimed you could use ‘reduced blanking mode’ in your graphics card settings to fix it as well.
Hope this tid bit helps,
Sam
Sam,
I saw your comment and thought I would give it a try. I ran out to my garage and located a DVI to VGA convertor, plugged it into my video card and then used a vga cable to attach it to the VGA port on my 204B. The problem is that my monitor is not seeing a signal. Is this because I’m using an incompatible VGA cable or is it because I must change some setting in the video driver? I’m running dual monitors and looked for driver/software settings but didn’t find any. You help would be appreciated.
Thanks, Stu
My monitor has now decided to work using the VGA cable and port but I cannot acheive the 1600 x 1200 resolution. I’ve messed around with the resolution and ATI catlyst setting with no luck.
Everything is working fine. I reset my monitor and the picture it popped into place.
The monitor is now rock solid and does not cut out. Apparently this was the issue with my 204B and not the caps.
I just repaired the 204B that was given to me this way too. Thanks for saving me some time! For those that don’t do switching power supplies for a living.. C110 and C111 are the filter caps for the 13V rail that then go through the inductor and power the green (solder masked) video board. The 3 330uF capacitors are the filter capacitors for the backlighting inverters. the 2 in two in the center of the board have a small ceramic capacitor across the leads under the board, which absorbs much of high frequency noise from the PFC Flyback transformer. There are no capacitors near the main bulk capacitors (the 3 right by the transformer) to take off the switching edges, leaving all the ripple to be absorbed by the electrolytics. Pretty harsh on them, not surprising that they get hot and vent. The unpopulated capacitor location just “above” the 3 in a row is also in parallel with the other 330uF capacitors. And can be populated as well if you want a little more supply filtering. I added some 10nF (0.01uF) 50V ceramic capacitors right across the bottoms of the replaced capacitors near the transformer to keep them happier. Of course, just replacing them with Panasonic and Nichicon capacitors probably was enough.
The two power ripple filtering capacitors C110 and C111 have a value (820uF) that Radioshack doesn’t carry. If you want to “fix it today” and not have to wait for mail order parts, consider the following. The purpose of the two 820uF is smoothing voltage ripple. In those situations it is okay to use a larger value. Both are wired in parallel, so the total capacitance is 2 x 820uF = 1,640 uF. I substituted two 1,000 uF/35V capacitors (standard at Radioshack) and all problems were resolved (24 hours ago as of this writing). Note that I used 35V versions instead of 25V to reduce heat development (and thus prolong life).
Hey, I have a question for you Hein.
I just bought the radioshack ones and arent they a little wide to fit both of them? Did you just cramp them both in??
Just repaired the fourth 204B this way.
I too have had problems with my 204B loosing the picture and then turning back on.. I found another post that said the culprits were likely to be at C110 and C111. I replaced those two caps with 820uf 25v caps but my monitor still goes blank. Do you think replacing the other caps you mentioned above would fix my problem or might by problem be on the other board?
Thanks, Stu
My only advice would be to replace the remaining caps. If that doesn’t solve the problem, then investigate the backlighting tubes or the HV transformers.
Good luck!
I ordered the other caps and will replace them soon. I will look at all the other caps on while I’m in there. Is there anything else that I should be inspecting while I have the “hood open”?
Again, my screen goes blank sometimes.
It only starts to act up once it has been on for a long period of time. Usually a couple of hours. Hopefully that info might be helpful to someone smarter than I to diagnose the problem.
I replaced all the caps. The monitor ran great for a day or two and now is “blanking out”again.
Can someone give me specific instructions on how to troubleshoot the backlighting tiubes or the HV transformers as mentioned above by Pavel?
Thanks!
Stuart, when you say ‘blanking out’, do you mean the screen just turns itself off, then back on? When it comes back on, is it at full brightness? If so, are you running 1600x1200x32 @60Hz via the DVI connector? If the answer to all three is ‘yes’, then you are likely running into the same issue I did (apart from the bad caps)… basically the converter chip inside the thing is *barely* able to keep up with that level of information flow, and occasionally throws up its hands and resets itself. A work-around given to me by my graphics card manufacturer is to set a custom resolution which runs at about 59.2Hz refresh. Since then, no problems
My 204B has the symptoms, however it doesn’t have the small slot mentioned in the disassambly instructions. Any info about disassembly would be appreciated.
Keep gently prying at the case with a plastic putty knife or similar tool — you’ll find one of the plastic snaps eventually. Getting past the first one is the most difficult part of disassembly.
I replaced all the caps except for the 450V one. After reassembling I get a constant blue power button light when power is applied. When plugged into a computer I get no result either way, and the power button does not appear to do anything. I went ahead and ordered the 450v cap, but have a feeling that will not solve this problem. Any suggestions?
That connector connecting the monitor logic board to the display matrix can be a [removed - please watch your language]. My guess is you have to make sure it is seated perfectly. I had to tape the wire in place because I’d accidentally destroyed the latch on one side of that connector.
Thanks for the great advice. I have a syncmaster 206 with the same problems. Three of the Capxon capacitor (2) 1000uf25v and (1) 470uf25v where bulging.
I will replace these parts later when I can find them locally. The shipping is too high for $1 in parts. ($6.90).
Thanks again for your help.
This is another thank you for sharing this information.
and 1920×1200 monitors are quite expensive, and I refuse to lose ~120 pixels in the vertical to the popular “1080p” monitors! Like many who commented here, my 204b just got out of Samsung’s warranty period.
You have saved me the US$300+ it would’ve cost me to replace my 204b. 1600×1200 monitors aren’t being made anymore
Thanks to your clear specs on the capacitors required, I ordered $2.50 worth (all caps you have listed except the big mother 450v one) + $2 shipping.
I only replaced the 3 caps that were clearly bulging and leaking some brown substance. The caps in the middle of the board (C304, C305) looked stellar as did the huge 450v cap – these were all capXon brand as well.
Here are some pics of the culprit capacitors!
http://img301.imageshack.us/i/c110brownscumcrop.jpg/
http://img301.imageshack.us/i/c110111112sideview.jpg/
http://img229.imageshack.us/i/c110111112sideviewclear.jpg/
http://img704.imageshack.us/i/c110111112topview.jpg/
For C110 and C111, I used these capacitors. They are slightly taller than the capXon ones Samsung uses, but they are not too tall – they fit just fine. They are 1-2mm taller than the heatsink they are located beside.
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=493-1556-ND&x=9&y=17
For C112 I used
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=493-1063-ND&x=14&y=19
Since I had never soldered before, for learning how to desolder, I found this to be a clear and picture-full guide.
http://www.hardwaresecrets.com/printpage/164
My monitor’s history in case anyone is interested:
It is a refurb from Samsung after my original 204b developed a yellow line of pixels across the screen (so my first 204b problem was unrelated to the inverter & capacitor problem). This refurb, about a year after owning it, started to take about 10 minutes to “warm up” before displaying a picture. Only until 2 weeks ago did the backlight flickering during normal operation start to occur.
I diagnosed the problem to be not with the backlight itself, but with the power going into the back light for one reason: The more dark pixels on screen, the darker the backlight got. I suspect this is because white RGB(0,0,0) requires no voltage (or little voltage) to be applied to the molecules sitting in each pixel/subpixel. White is the default color of a pixel when no voltage is applied?
Yesterday the backlight refused to turn on no matter if the screen was entirely white. So today I removed the leaking capacitors and replaced them with new ones – the monitor is working as-new! Thank you again. If this were real life I would hug you.
Thank you so much! I have patched up 2 SyncMaster 204B Monitors with your guide and user comments! Ordered from Digi-Key. My 450v capacitors in the monitors were both the 150UF not the 100 as in the guide, but I caught that before ordering.
Digi-Key Item #s that I got (worked great)
P13123-ND = CAP 330UF 25V Elect EB Radial (need 3 per monitor @ $0.36/each)
P11222-ND = CAP 820UF 25V Elect FC Radial (need 2 per monitor @ $1.30/each)
P14104-ND = CAP 150UF 450V Elect TS-HC (need 1 per monitor @ $4.50 /each)
The 450v cap I ordered had short pins, but I cut the pins off as close as I could to the the old capacitor , then just soldered it together.
Did both monitors in 80mins… (50mins for the first monitor/30mins for the second).
Remember – Check the Polarity!
were can i find 820uf 25v cap and 330uf cap
Please see the “Caveats” section on how to pick the right capacitors on Mouser. You can also use DigiKey, Farnell, etc.