Repairing the Samsung 940MW LCD TV

January 19, 2010 by
Filed under: Uncategorized 

Today’s post will cover the repair of the Samsung 940MW LCD TV or other models using the IP-48135T or BN44-00116B power supply. If you have a Samsung SyncMaster 940MW monitor that either has a blinking power light or a very dark picture or makes popping noises then this should help get you back running. 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 capacitors, qty(2) 1000uf 10v capacitors, qty(2) 820uf 25v capacitors qty(1) 330uf 10v capacitor and qty(1) 330uf 25v capacitors. We sell a repair kit with all of the parts for $14.00 This is not guaranteed to solve all problems but in most cases this is the issue with this model.

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

Here we have a non functional Samsung 940MW 20″ LCD monitor. This one has a dim picture and popping noise when you first power up the monitor but the symptoms could be no power or a flashing power light too.

First you need to remove the power cable, signal cable and the stand. To remove the stand remove the 4 screws as shown in the picture below. After the stand is off the you will find a third case screw in the center of the lower back under the stand.

The case will pop open if you insert a small flat screwdriver between the 2 halves and apply a gentle pressure. Once it starts opening just use your fingers and work your way around the screen.

After the back case is removed you will need to unscrew the 5 screws holding the metal shield in place over the power supply and CPU board as show here. After the screws are removed just lift the shield and set it to the side for later re-installation.
With the shield off we can now see the board that we will be working on. Remove the 3 screws holding the power supply board in place they are circled in Yellow. Next disconnect the 2 backlight power plugs and the black CPU power plug as shown circled in Red.

The capacitors you need to replace are circled in the picture on the right. Use solder braid and remove the bad caps and solder in the replacement caps. Be sure to replace them in the proper polarity, you will see a stripe on the side. The stripe is the negative lead. Just reinsert the new caps with the stripe going the same direction. The values and part locations are listed here:

680uf 25v – C316, C315

1000uf 10v- C109, C110

330uf 25v – C113

330uf 10v – C117

820uf 25v – C111, C112

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.
If you need a replacement coax connector they are available from Amazon here:
Samsung Coaxial Connector for Syncmaster Monitor

Facebook Twitter Email


76 Comments on Repairing the Samsung 940MW LCD TV

  1. Richard on Tue, 9th Mar 2010 2:37 pm
  2. I forgot what was the order of the pink and blue wires at the battery suply board and I would know it. does anyone know? I can’t see it clearly at the picture. Thanks

  3. admin on Tue, 9th Mar 2010 2:44 pm
  4. The order of the pink and blue backlight connections does not matter. Each tube has a separate driver so they can connect to any of the sockets on the inverter board.

  5. Richard on Tue, 9th Mar 2010 2:48 pm
  6. Great! thank you very much!

  7. Richard on Tue, 9th Mar 2010 2:48 pm
  8. by the way awesome tutorial

  9. Harry B on Tue, 16th Mar 2010 12:59 am
  10. Hello.
    I have been reading this part of your site.
    I can read and speak English, but understanding all, sometimes a bit difficult.

    What i do understand, is that this repair manual allso should be useful, when the screen does not realy turn of, and the green light keeps blinking after pushig the powerbutton?

    Since yesterday, my screen does not turn off when i push the power button, disconnecting the power cable is the only way tot turn it of.
    I am using it as an PC screen, and it gets into screensavemode normaly, and starting up when using mouse or press any keyboardbutton.

    But turning of with the powerbutton does not work.
    I could not find my remote control, seems to be anywhere in the house, so i could not test this function on remote control.

  11. SHAWN on Sun, 21st Mar 2010 7:20 pm
  12. I have a samsung syncmaster 940mw s (the model number has an s after the mw, not sure if it matters)

    However, I disassembled my monitor to remove the power board, and it’s different than what is pictured above. I do not have the two top capacitors, and my capacitor location numbers are different.

    680uf 25v – C316, C315 (I do not have these numbers on the board, nor do I have that size capacitor. what I do see is c303 and c304, they are smaller but in the same general area and are the only two capacitors in that region.)

    Just curious if I should try to replace the rest and not worry about those two, or if that wouldn’t work. Also, if I buy one of your kits will it include all the parts I need for this board? The numbers on the two smaller capacitors are “SX 33uf 25v”

  13. CCL_TECH on Sun, 21st Mar 2010 7:29 pm
  14. Hello,
    We are adding that version of the power board to the post, it is a WD-17. Your board does not use the 680 caps but it uses an extra 330uf 25v cap at position C302. The kit we have will come with the extra cap, you will just have the extra 680 caps after the repair is done.

  15. Harry B on Mon, 22nd Mar 2010 6:16 am
  16. As described above, i first could not find the remote control.
    I found it, and with remote control i can normaly turn on and off.

    Do you think the problem is in the caps?

  17. Mason on Wed, 31st Mar 2010 12:25 pm
  18. Great instructions I must say, but I ran into a problem after I put all the parts back together.

    When turning the monitor on, the power light comes on but the backlight doesn’t turn on with it. I can see a vague picture in the monitor, so I know it works to an extent.

  19. admin on Wed, 31st Mar 2010 12:45 pm
  20. Hello,

    Two things, first what brand and series capacitors did you use for the repair. If they are not rated for use in High frequency switching power supplies then they could be causing he problem. Second, check the small green fuse in the middle of the power supply board. You can check it with a standard multimeter set to either OHMs or continuity. Th fuse should show either very low OHMs on that setting or the meter should beep if set to continuity. Get back with us with this information.

  21. Eric on Sun, 4th Apr 2010 5:31 am
  22. thanks for this solution.
    5,50 euro and a little work, fixed my Samsung

  23. lee on Thu, 8th Apr 2010 10:16 am
  24. Hi this seems to be the solution for my tv. I am a novice to this kind of repair, so please bare with me!!

    I would be happy to buy components from you if you ship to uk. However if not, what size of each component would I need. As I have looked at various retailers and there are various sizes to the specs above.

    Please help. Regards Lee

  25. admin on Thu, 8th Apr 2010 10:49 am
  26. Yes, We ship to the UK. You can use the Buy Now link on the page to order and we can ship the kit the same day.

  27. lee on Wed, 21st Apr 2010 6:35 am
  28. just one other question before ordering. Does the fact I have a 240v tv make any difference to the power board, or would that just be a different transformer but comp will be the same???

    Regards. Lee

  29. CCL_TECH on Wed, 21st Apr 2010 6:47 am
  30. The board is the same, the transformer is different.

  31. lee on Wed, 21st Apr 2010 6:51 am
  32. Thanks. I’ll get ordering then!!!

  33. John on Mon, 26th Apr 2010 6:46 am
  34. Im going to attempt this too, I got the blinking power light and after pressing the power button a few times it will power on and initializing it would make a pop sound(like static feedback). So the symptoms seem the same. My question is when I have it on there is a pretty noticable hissing sound. Do you guys know if this is related to the bad caps?

  35. admin on Mon, 26th Apr 2010 6:49 am
  36. Hello,

    Yes, The hissing sound is caused by the capacitors in the power board not filtering the power correctly.

  37. John on Tue, 27th Apr 2010 11:34 am
  38. Well awesome, just made my order and hoping to receive them soon. Got 2 kits and just wish me luck, hope it fixes my screens.

  39. Chrismark on Fri, 30th Apr 2010 8:56 am
  40. WOW, my Smasung works now!
    My board is a little different, (as describe by SHAWN) so they condensatorer by the transformer, I have not changed. Mine was completely dead with no lights and sound. I had to perform image adjustment after assembly.
    Thanks for advice and kit.
    Chrismark from Denmark.

  41. lee on Tue, 4th May 2010 9:49 am
  42. just received my kit. However there is no 330uf 10v. But there is an extra cap!

    There are 3 x 330uf 25v. 2 of which are hd942 and 1 x B0950

    Please help. Confused novice here!! LOL.


  43. lee on Tue, 4th May 2010 11:34 am
  44. Thanks for email. Will use 25v in place of 10v as suggested.

    (for others ref-)

  45. Chrismark on Mon, 10th May 2010 6:02 am
  46. John …
    I sent my order on 17 April 2010.
    The letter was sent from the U.S. on 20 April 2010.
    We’ve had aircraft problem in Europe.
    On April 30 I received the letter.
    It’s OK. And my Samsung still work.

  47. Paul J on Mon, 17th May 2010 12:13 pm
  48. I have one of you repair kits already and am currently trying to desolder using some solder braid… however the solder on the board will not melt!
    I’m using a 15w solder… so what do I need?


  49. robert on Wed, 19th May 2010 2:36 am
  50. hi i have this model monitor but as soon as i plug it in with out touching the power button it just flickers was just wanting to no if this is still the same problem as you have descibed here
    when i press the power button i get noughing no power up the screen just flickers with no pops or any thing hope to hear soon thanks

  51. admin on Wed, 19th May 2010 9:46 am
  52. Yes, That is an indication that the power supply is not stabilizing the voltages correctly. When you plug the unit in the power supply should start up and the voltages should settle to the correct voltage for operation. Even before you press the power button the unit is on because it is waiting and watching for signals from the remote control unit. The flickering you see is caused by the power supply trying to settle down and failing so it keeps resetting which is making the unit flicker. If you replace the capacitors in the power supply as show you should be back up and going.


  53. admin on Wed, 19th May 2010 10:00 am
  54. To do the repair you will need to use at least a 30watt soldering iron, 15watt units are much to small for most repair work.

  55. Sebastian on Wed, 19th May 2010 11:09 am
  56. I just had my first desolder + soldering experience for 12 years.

    It started off hard… but by the end it was going pretty smoothly!

    The monitor turned on first time :) Cheers!

  57. admin on Wed, 19th May 2010 12:32 pm
  58. Great,

    Another one saved from the trash pile!

  59. lee on Thu, 27th May 2010 6:01 am
  60. Undertaking this project was way out of my zone. Only electronics i’ve ever done, was 20 years ago, making a basic buzzer at school, lol.

    When I got the Unit open, though model 940MW. I discovered the same situation as Shawn in a few post’s back. (940MWs power board). Followed Techs instructions, took my time. JOB DONE!!!!!! Just hope it last’s, lol.

    If I can do it, you doubters can!!!! Go for it!!!

  61. spain on Mon, 13th Sep 2010 12:43 pm
  62. Thank you
    samsung 226bw
    Another one saved .

  63. Bob R on Fri, 8th Oct 2010 7:35 pm
  64. Replaced all the capacitors for the second time and guess what? IT WORKS Must have been a bad capacitor! Thank you ! You saved another from the scrap pile

  65. Mick ( UK ) on Wed, 17th Nov 2010 12:54 pm
  66. Thanks a lot guys shipped to the UK, took about 10 days,no problems. Cost £8.00 and 1 hour of time. All up and running again. Thanks once again!!!
    PS Great Tutorial

  67. Robert From L.A. on Mon, 27th Dec 2010 8:54 pm
  68. Corporate Computer Rocks!

    US$14 and an hour of my time, and yesirree, that decade-old Samsung is working again! After this (andbringing a couple of LaCie drives back to life), am calling this the “Millennium of the Power Supply”.

    Thanks for sending us adventurous few back to our Electronics 101 roots! My three and a half year old is now destined to phollow in our phootsteps.

  69. Dave (MD) on Fri, 21st Jan 2011 5:42 am
  70. Another monitored resurrected!

    It’s been about a decade since I soldered any electronic components, but its just like riding a bike. Detailed instructions, pictures, and comments were extremely helpful and I had the monitor fired up in about 90 minutes.

  71. JD on Fri, 28th Jan 2011 12:10 pm
  72. I had a WD-17 board as mentioned in comment 7. The kit had the extra capacitor, and my monitor is now back up. There were a few additional screws to be removed, but they were pretty obvious. Thanks for providing the kit and how-to!

  73. DuctTapedGoat on Tue, 8th Mar 2011 3:41 pm
  74. I got a quick email response.

    We have changed the values on those 2 caps because in our repair center we have found those hold up better than the original values.

    I soldered in that last and final cap, and that did it! It’s working perfectly. A couple of the caps tested good, but I did the full replacement for good measure.

    Thanks so much CCL!

  75. ERNIE GULDEN on Tue, 18th Oct 2011 12:01 pm
  76. Excellent instructions and pictures.
    Received parts yesterday; up and running today.

    You’ve got your act together!

    Ernie Gulden
    Denison, TX

  77. Martyn on Wed, 11th Jan 2012 2:36 pm
  78. Excellent instructions – my 940MW was having trouble switching on and then what i thought was the backlight went on the coaxial input so i had a very feint picture. However when i play a DVD there is no problem with the picture. I have replaced 4 capacitors and the TV switches on fine but the coax TV picture is still the same. Any ideas greatly appreciated. UK model.

  79. CCL_TECH on Wed, 11th Jan 2012 3:49 pm
  80. You should change all of the capacitors on the power supply board, not just the ones with visible bulging. The capacitors can start to fail before they start to bulge and this can throw off the voltages in the power supply which could cause the poor picture quality if the tuner is not getting the correct power.

  81. Mark on Mon, 16th Jan 2012 2:46 pm
  82. My problem is a little different:
    My 940mw turns on fine, and picture looks perfect, but after 20-30 mins (through DVI) the screen goes black. If I turn it off and on again, or cycle through inputs back to DVI, it will work again, but for a shorter time.
    Is it overheating? Do you think the problem is those same capacitors?

  83. admin on Mon, 16th Jan 2012 2:51 pm
  84. That sounds like heat related power supply issues. Digital signals require more power from the power supply and when it is overheating it will drop out. Cycling through the inputs drops the power down temporarily and the unit regains a picture. I would bet that if you open the case and look at the board you will find the capacitors are bulging. Check it and let us know what you find.

  85. Mark on Mon, 16th Jan 2012 3:27 pm
  86. Thanks for the quick reply!
    If that’s the case, do you think replacing the capacitors would solve the problem?

  87. admin on Mon, 16th Jan 2012 3:46 pm
  88. Yes, That should get it back going again.

  89. Martyn on Tue, 17th Jan 2012 3:02 pm
  90. Have replaced all capacitors as requested but still feint picture. Cannot understand that when I play a DVD through the scary the picture is perfect? Any further instructions?

  91. Mark on Thu, 8th Mar 2012 5:42 am
  92. Me again! Replaced those capacitors with your pack, problem persists…

  93. martin on Wed, 18th Apr 2012 2:17 am
  94. Got your kit & fitted all caps, But I’m left with one???(330 25v).
    my monitor is 240v model. Do I use this, or shouldn’t it be in the kit???

  95. CCL_TECH on Thu, 19th Apr 2012 9:49 am
  96. Hello,

    There are two different versions of the power supply board in the 940MW. Our kit has the parts to rebuild both versions, one uses the 330uf cap and the other uses qty 2 of 680uf caps so either way there will be a part left over after the repair. This is normal and you used all the ones needed for your board. You should be able to reassemble the unit and have it power right up.

  97. martin on Fri, 20th Apr 2012 2:28 am
  98. Just put it back together, & its dead,no lights nothing.
    caps did need changing.but looks like something else is wrong.
    any idea’s.

  99. martin on Thu, 7th Jun 2012 10:14 am
  100. No idea’s or not interested now you’ve taken my money???????

  101. Miro on Mon, 16th Jul 2012 10:47 am
  102. Hi,
    I have a slightly different problem with SyncMaster 940MW (Europe – 240V) – first, I had to press the power button up to 25 times (built-in or remote) to start it up and now it just shows picture for 1 second and goes blank again – same if I switch around the source. The sound is ok. I wonder, could this be resolved by changing the capacitors?
    Thanks a million.

  103. admin on Mon, 16th Jul 2012 11:00 am
  104. Yes,

    The capacitors can cause that type of issue. When they start to fail they can not filter the output voltages correctly. Repeating the power up cycle by pressing the power button will eventually allow them to build up enough charge to allow the power board to start up but it can not hold the charge enough to power the unit so it turns back off again. Open your unit and check the caps, I would bet you find them damaged.

  105. Miro on Thu, 19th Jul 2012 7:25 pm
  106. Hi,
    Thanks for the advice. You were right – 3 of the caps were damaged. However, even after changing all 8 of them, the problem persists. Is there anything else I could try to do?
    Thanks a million.

  107. kodi on Thu, 16th Aug 2012 7:14 am
  108. Just quick questions – are the caps in the kit rated 85 degrees C or 105 degrees?

    (and thanks for the tutorial – looks like my 940MW will have a second chance ;) )

  109. CCL_TECH on Mon, 20th Aug 2012 9:36 am
  110. All of the capacitor we use in our kits are low ESR, High ripple current and high temp 105c. These are the ratings that are needed for capacitors in high speed switching power supplies like the ones used in LCD monitors and computers

  111. EJ Kukoly on Sun, 23rd Sep 2012 4:26 pm
  112. Bought the kit… and the monitor is back to it’s former greatness. I had never soldered before… and it definitely wasnt pretty, but it worked. Thanks!!!

  113. CCL_TECH on Sun, 23rd Sep 2012 5:01 pm
  114. Pretty or not as long as it works!! It’s really amazing that most computer and TV shops say that its not worth repairing when the parts are so cheap and its fairly easy to do. Another one saved from the trash pile and your wallet is happy too.

  115. tim on Mon, 24th Dec 2012 12:59 pm
  116. was given the 940mw as a nice paper weight, found your sight, ordered the capacitor kit (5 were bulging on top)
    1. First time soldering
    Unit started up on the 1st press of the ON button!
    Thanks guys for the tutorial !

  117. Pan on Thu, 3rd Jan 2013 12:59 pm
  118. Just wanted to let you know guys at ccl-la that my kit just arrived through the post today. It took over a month, but I guess it’s normal considering cheap mailing, long distance (Greece) and holiday season. I hope this will work so that I can give a new life to my screen (symptom: blinking led responding to the remote, but nothing else) and use it as a tv monitor or something. I ‘ll give it a try and report back to you with the good news hopefully. Happy New Year to all!

  119. Joe on Fri, 4th Jan 2013 1:24 pm
  120. Just wanted to say many thanks. Had a Samsung 940MG purchased around 2007. Within the 3 year warranty, my one was swapped out 3 times by Samsung for a failing backlight, and was eventually replaced by PC World for an LG instead (which has been fine since, touch wood.)

    My dad bought a 940MG about the same time, and his had just died. Could see feint grey lines on the screen when I shined a torch on it, but the symptoms sounded the same as this (he’d had to keep switching on and off until eventually it stopped).

    3 capacitors were leaking when I took it to bits, replaced all 8 to be on the safe side. Slightly different layout to the 940MG, but fired it up and despite my naff soldering skills, all working brilliantly.

    I always wondered if I was killing them by overloading them with connectivity (had all ports in use), but hopefuly it was just these naff capacitors.

  121. david mansworth (United Kingdom) on Sat, 12th Jan 2013 5:00 pm
  122. Having had a 940 in the cupboard for quite some time. as the faults as listed above detail.
    I was about to but a new small TV/Monitor for the desk area in the Kitchen. as I am now working in windows and need a larger monitor to view pages in tile screen mode.

    your instructions to me are Super Clear and the task in hand is easy to undertake. esp as electrics are involved in my work.

    I am no Green Save the Planet type just hate having to spend out two or so hundred pounds when a couple of hours work and £8 of parts will do the job.
    Many thanks. if it cures the fault and monitor/tv can be used again then a £25 donation to Charity (cancer ?) will be made in honour of your greatfully received advice and directions.

    Have book marked your site for future use.

    Many thanks

  123. Peter (Switzerland) on Thu, 7th Feb 2013 10:29 am
  124. Great instructions!!! And it really works and saved my good ol’ 940mw :-) THX!

  125. Ali Baba on Sun, 3rd Mar 2013 6:59 am
  126. Thank you so much!!!
    Amazing how people take the trouble to post and help others through internet.

    Ali Baba (Nickname)

  127. Paul on Tue, 2nd Apr 2013 12:13 am
  128. Hi there
    I have a Samsung Syncmaster 940MG with problems with having to push power button at least 8 times to get it to work.
    Will this capacitor kit be compatible for my monitor?
    Also do you recommend to leave the power button on stand by or will it make no difference in trying to turn it back on?
    Many thanks

    From London UK

  129. CCL_TECH on Tue, 2nd Apr 2013 2:57 pm
  130. Hello Paul,

    Yes, The 940MW capacitor kit works with the 940MG units. The last letter designates the destination country. The power button standby will not make any difference in the power supply life. Here is the link to get the kit:

  131. Ko (Netherlands) on Tue, 2nd Apr 2013 3:33 pm
  132. Hello,
    After exchanging the 8 caps, my monitor is working very well again !!!
    Thank you very much for the tutorial !!
    Groeten uit Nederland,

  133. Dennis Barton on Sun, 28th Apr 2013 12:32 pm
  134. Great article on repairing the Samsung 940MW. After replacing a handful of capacitors for $14 and a half hour or so of time, my TV/monitor is now good as new. There were a few minor differences between my unit and your description, but the instructions weren’t hard to follow at all. Thanks!

  135. Tony Organ on Tue, 13th Aug 2013 4:29 pm
  136. Hello, I live in New Zealand and now retired at 75 years old. I purchased one of your capacitor kits for my Samsung 940MG(R) and followed your online instructions and photos.Monitor working like new again. Thanks for the great Information and parts service.

  137. Andy on Fri, 29th Nov 2013 11:36 am
  138. I bought the repair kit for the 940mw. I have the same problem as Shawn posted below, but I did not receive an extra cap for the C302. Can u please send it to me

    SHAWN on Sun, 21st Mar 2010 7:20 pm I have a samsung syncmaster 940mw s (the model number has an s after the mw, not sure if it matters) However, I disassembled my monitor to remove the power board, and it’s different than what is pictured above. I do not have the two top capacitors, and my capacitor location numbers are different. 680uf 25v – C316, C315 (I do not have these numbers on the board, nor do I have that size capacitor. what I do see is c303 and c304, they are smaller but in the same general area and are the only two capacitors in that region.) Just curious if I should try to replace the rest and not worry about those two, or if that wouldn’t work. Also, if I buy one of your kits will it include all the parts I need for this board? The numbers on the two smaller capacitors are “SX 33uf 25v” – See more at:

  139. Radu on Sat, 25th Oct 2014 4:43 am
  140. I just replaced the capacitors on my Samsung 940mw and instead of the blinking red light and the sounds it was making, now the tv starts ok, i can hear sound but after 1s the screen goes very dim(i need to put a flashlight on it to see something)… What can i do?

  141. Radu on Sat, 25th Oct 2014 6:23 am
  142. Blinking Green Light, idk why i typed red. Can anyone help me?

  143. Samsung TV Deals on Mon, 17th Nov 2014 9:49 pm
  144. This is the perfect web site for anyone who hopes to find out about this topic.
    You understand so much its almost hard to argue with you
    (not that I really will need to…HaHa). You definitely put a
    new spin on a topic that has been written about for decades.
    Wonderful stuff, just excellent!

  145. Mike Kwiatkowski on Wed, 4th Mar 2015 5:48 pm
  146. I promised a down-trodden lady–a friend of a friend–that I would help her get a TV for her kids, and found a Samsung unit at my local Goodwill for $20.00. I got it for $5.00 and learned it was worthabout that much once I got it home.

    An on-line search led me here & I ordered one of your kits for $14.95, and waited for it to come. I had to get a few additional items to do the job (De-soldering iron, liquid flux applicator & a tip cleaner) but I had the job done quickly & the unit was then worth the original price, and the woman I gave it to was grateful.

    Thanks guys, for helping me build confidence & skiils as a electronic repair hobbyist… and making a charitable effort come through.

    [...] handy with a soldering iron, you can replace the 10 bad caps with fresh ones in around an hour, and disassembling this particular monitor is pretty simple. Note that Samsung used two different styles of power supply board in these displays, so you might [...]

  147. Eunice on Wed, 26th Sep 2018 9:15 am
  148. Greate article. Keep posting such kind of information on your blog.
    Im really impressed by it.
    Hello there, You’ve performed a great job. I will certainly digg it and forr my
    art suggest to my friends. I’m sure they will be benefited fro this site.

  149. ALEXANDRE DA SILVA BRITO on Mon, 10th Dec 2018 10:24 am
  150. Quanto custa um display da samsung syncmaster 940mw s? Pois caiu água no meu monitor e danificou o display.

Tell me what you're thinking...