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

45 Comments on Repairing the Samsung 940MW LCD TV

Richard on Tue, 9th Mar 2010 2:37 pm


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

admin on Tue, 9th Mar 2010 2:44 pm


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.

Richard on Tue, 9th Mar 2010 2:48 pm


Great! thank you very much!

Richard on Tue, 9th Mar 2010 2:48 pm


by the way awesome tutorial

Harry B on Tue, 16th Mar 2010 12:59 am


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.

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”

CCL_TECH on Sun, 21st Mar 2010 7:29 pm


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.

Harry B on Mon, 22nd Mar 2010 6:16 am


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?

Mason on Wed, 31st Mar 2010 12:25 pm


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.

admin on Wed, 31st Mar 2010 12:45 pm


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.

Eric on Sun, 4th Apr 2010 5:31 am


thanks for this solution.
5,50 euro and a little work, fixed my Samsung

lee on Thu, 8th Apr 2010 10:16 am


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

admin on Thu, 8th Apr 2010 10:49 am


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.

lee on Wed, 21st Apr 2010 6:35 am


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

CCL_TECH on Wed, 21st Apr 2010 6:47 am


The board is the same, the transformer is different.

lee on Wed, 21st Apr 2010 6:51 am


Thanks. I’ll get ordering then!!!

John on Mon, 26th Apr 2010 6:46 am


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?

admin on Mon, 26th Apr 2010 6:49 am


Hello,

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

John on Tue, 27th Apr 2010 11:34 am


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.

Chrismark on Fri, 30th Apr 2010 8:56 am


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.

lee on Tue, 4th May 2010 9:49 am


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.

Regards..

lee on Tue, 4th May 2010 11:34 am


Thanks for email. Will use 25v in place of 10v as suggested.

(for others ref-)

Chrismark on Mon, 10th May 2010 6:02 am


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.

Paul J on Mon, 17th May 2010 12:13 pm


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?

Thanks

robert on Wed, 19th May 2010 2:36 am


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

admin on Wed, 19th May 2010 9:46 am


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.

CCL_Tech

admin on Wed, 19th May 2010 10:00 am


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.

Sebastian on Wed, 19th May 2010 11:09 am


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!

admin on Wed, 19th May 2010 12:32 pm


Great,

Another one saved from the trash pile!

lee on Thu, 27th May 2010 6:01 am


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!!!

spain on Mon, 13th Sep 2010 12:43 pm


Thank you
samsung 226bw
Another one saved .

Bob R on Fri, 8th Oct 2010 7:35 pm


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

Mick ( UK ) on Wed, 17th Nov 2010 12:54 pm


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!!!
Mick
PS Great Tutorial

Robert From L.A. on Mon, 27th Dec 2010 8:54 pm


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.

Dave (MD) on Fri, 21st Jan 2011 5:42 am


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.

JD on Fri, 28th Jan 2011 12:10 pm


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!

DuctTapedGoat on Tue, 8th Mar 2011 3:41 pm


I got a quick email response.

Hello,
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.
CCL

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!

ERNIE GULDEN on Tue, 18th Oct 2011 12:01 pm


Excellent instructions and pictures.
Received parts yesterday; up and running today.

You’ve got your act together!

Thanks,
Ernie Gulden
Denison, TX

Martyn on Wed, 11th Jan 2012 2:36 pm


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.
Thanks

CCL_TECH on Wed, 11th Jan 2012 3:49 pm


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.

Mark on Mon, 16th Jan 2012 2:46 pm


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?
Thanks!

admin on Mon, 16th Jan 2012 2:51 pm


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.

Mark on Mon, 16th Jan 2012 3:27 pm


Thanks for the quick reply!
If that’s the case, do you think replacing the capacitors would solve the problem?

admin on Mon, 16th Jan 2012 3:46 pm


Yes, That should get it back going again.

Martyn on Tue, 17th Jan 2012 3:02 pm


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?
Thanks

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