Instructables

Repair Samsung LCD TV -Relay Clicks, Shuts Off, Won't Come On

Picture of Repair Samsung LCD TV -Relay Clicks, Shuts Off, Won't Come On
DISCLAIMER - If you attempt to repair your own set, expect to void any warranty that might still exist.  If you do additional damage, it's your own responsibility.  Further, you are working with an appliance that is powered from you house mains.  There is risk of shock with the potential of death or serious harm.  Know what you are doing, and how to work safely with an electrical appliance.


Recently my 3+ year old 40" Samsung LCD TV started taking a long time to start up, with several cycles of relays clicking.  In searching the net I found that others were having similar problems.  Apparently, Samsung's power supply on several LCD models was somewhat under-designed, with four capacitors that slowly fail over time and which leads to the symptoms in the title.
There are several options for repair: 1) Take the set to a qualified repair shop (est $300 - $500). 2) Buy a new, replacement, power supply ($100 - $175). 3) Replace the offending capacitors ($4.00 - $15.00)

I chose option 3, spending $15.00 for a Samsung repair kit (contains 4-1000 uF, 25V, 105 degree C capacitors and "instructions").  If you want to keep the costs to a minimum, you can order an appropriate set of capacitors from Digi-Key or Mouser for about $0.65 each + s/h.

Tools you need:
Phillips screw driver able to reach recessed screws (about 1" deep)
Soldering Iron for general purpose electronic components.

Note: According to the Samsung repair kit instructions, this repair works with the following models:
LNT4042H
LNT4042HTX/XAA
LNT4053HTX/XAA
LNT4053HX/XAA
LNT4053HX/XAC
LNT405HAX/XAA
LNT4061F
LNT4061FX
LNT4061FX/XAA
LNT4061FX/XAC
LNT4061FX/XAP
LNT4065XF/XAA
LNT4066F
LNT4066FX/XAA
 
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Step 1: Remove the back of the set

Picture of Remove the back of the set
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Place monitor face down on a cushioned table. Remove screws from cover and remove screws from the stand. (If stand is attached)

I have an optional wall mount setup, requiring removal of the wall mount hardware from the rear cover - a total of 4 screws.

Step 2: Disconnect and Remove the power supply


There are seven screws securing the power supply, as well as the various cable connecting to other components.  Remove the cables, remove the screws, and then lift out the power supply.
IMPORTANT NOTE - While capacitors are not particularly sensitive to Electrostatic Discharge (ESD), most of the components on the power supply and other boards ARE!  Take appropriate measure to avoid static discharge (grounding straps, etc.), or risk totally frying your set's electronics.  Should this occur, you're no longer facing an inexpensive repair.

Step 3: Identify, De-Solder, and remove the failing capacitors

Picture of Identify, De-Solder, and remove the failing capacitors
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There are four electrolytic capacitors to be removed: CM812, CM811, CM817, CS806.  These are clearly noted on both the front and rear surfaces of the power supply's circuit board.  (If you need a tutorial on how to de-solder "thru-hole" components, there are both text and video available on the net.)

You will likely see that the four capacitors of interest display bulging caps, and may even be leaking material.  On my set, only one showed any leakage, but all four were bulging.  The circuit they were used in is marked at 5.4V.  Based on my readings in electronics, capacitors should, in general, be rated for a voltage that is at least double the planned circuit.  Given that the original capacitors are rated at 10V, it would seem to indicate that fudging a bit here can lead to premature failure. 

Step 4: Solder-in the replacement capacitors

The capacitors are polarized.  This means you MUST pay attention to the positive and negative leads on the capacitors.  The polarity is clearly identified on both the capacitors, there is a stripe down the side of a polarized capacitor with the minus sign, and the circuit board (both front and back indicate the polarity).  Failure to match polarity is BAD.  At the best, the capacitors will fail, in the worst case, they explode, and I assume, don't do anything good to the circuit board either.

Step 5: Replace the repaired power supply and attach the rear cover

Picture of Replace the repaired power supply and attach the rear cover
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Replace your newly repaired power supply, connect the internal cables to the other components.  Re-attach the rear cover, stand (if used), or wall mount brackets. Attach the external cables (Video, Antenna, etc.).  And, finally, plug in the power cord.  If all has gone well, press the power button and you'll see your set power up as it did when it was new.

NOTE:  The photo of my working TV is NOT representative of the image!  The horizontal striations are an artifact.

Step 6: Other Resources

You may find the following useful:

Samsung LCD Power Supply Repair Kit - BN44-00167A
Samsung Replacement Power Supply - BN44-00167F
Digi-Key - www.digikey.com
eastx9 months ago
Digi-Key no longer sells the repair kit, btw.
310susanf2 years ago
IF YOUR SAMSUNG TV STILL HAS NO PICTURE AFTER THE CAPACITIORS ARE REPLACED READ THIS.
TV model is LN46A540P2FXZA 3.5 YRS OLD no picture but we have sound.
SHORT VERSION
1. replaced the bulging capacitor and the one next to it. NO PICTURE.
2. Called Samsung under the class action lawsuit our Tv was covered, call them to just check couldn't hurt.

3. TV repair came out twice first replaced the same 2 caps that we had replaced prior, still no picture but we knew that. Came back with a power supply board and replaced it, still no picture. These are the 2 things that were authorized by this lawsuit to replace, that's it and we got both.

3. Then we went to ShopJimmy (I have nothing to do with this site) purchased 2 inverter boards found the place online and the information by reading a lot.

Remember this is the short version. From everything we read online the suspect was probably the back light we replaced the right and left side inverter boards. and the parts added up to less than $45.00 including shipping which was free.

Ordered online on a Sunday and we had the parts by Wednesday, took the tv apart and replaced the 2 inverter boards located on our model on the left & right side. The hardest part about this repair is taking it all apart and putting it all back together again, the inverter boards snap in where the old ones snap out of and they came out pretty easy. We put it all back together and plugged it in and we have ONE BEAUTIFUL TV PICTURE AGAIN!!!
Inverter boards (on our model) are located under a piece of sheet metal so you have to take that off first.
these are the parts we replaced for the last and best fix if I can get them to load on this site.
DSC05180.JPGDSC05181.JPGDSC05182.JPGDSC05183.JPGDSC05184.JPGDSC05185.JPG
hamsammy2 years ago
From sstiefel on another page.

"I called Samsung. There is some settlement on some brands of Samsung LCD TV's sold before 2008. I spoke to a nice lady at 888-899-7602 who asked for my model number and serial number, then took my info to arrange for a local repairman to come by within 1-2 days to check the capacitor and replace the power components at no charge. SO glad I read this page and called Samsung before having it shipped off and spending a lot of money. Hopefully I will get extended life from this TV set with this servicing."

I called and got a tech to come out for free!
nursebob3428 (author)  hamsammy2 years ago
Good information. Thanks for sharing it.
FWIW, my repair seems to be holding up so far.

Bob
landtuna2 years ago
Thank you so much for this! I have an LNT4061F. I replaced two of the capacitors, both 2200uF. They had different numbers on the board, but both had bulging tops. The originals were 10V, and I replaced them with 25V.
nursebob3428 (author)  landtuna2 years ago
Sounds like a reasonable approach.

When mine failed, I assumed it was due to some design error/failure on Samsung's part. But, in the interim I found that the "Bad Capacitor" tale has a much broader impact, and was far from limited to just Samsung's TVs.

http://en.wikipedia.org/wiki/Capacitor_plague

Bob
Ittiz2 years ago
This guide helped me. My TV has been doing this for a year. I've been putting off fixing it because it was easier to wait for it to turn on than risking breaking it completely. Until yesterday when we turned it on before I left for work and when I came home some 9 hours later and it was going click clack (never took more than 2 hours to turn on before).

Unfortunately none of the local stores had the needed capacitors. Also I found what the TV had was two 1000 μF 25v 105C capacitors and two 2200 μF 10v 105C capacitors, not four identical 2200 μF 10v 105C capacitors. All of them were bulging and/or leaking. I found and old mother board laying around, which had a bunch of 1500 μF 16v 105C capacitors. They were the closest thing I had so I took four from there and put them. What do you know, it worked.
nursebob3428 (author)  Ittiz2 years ago
Cool! Good to hear.
glittalogik3 years ago
I just scored a free LA46N81BDX with click-of-death from a friend who used the fault as an excuse to upgrade. There were two blown 10v 2200uF 105degC capacitors. Replaced them for total cost of $2.20 and it's working perfectly!
nursebob3428 (author)  glittalogik3 years ago
Glad you saved the $$$ and that the instructions made some sense...

bob
pstretz3 years ago
The set I have, LN-T4671F, was actually covered under a free replacement from Samsung. They were able to schedule a person to come out to my home and replace the whole power supply on my set the day after I called for support. It was only about a half hour to do the repair and I didn't pay anything. Comparing the two supplies, they actually had different value capacitors. I don't remember the values now, but the blown ones had lower values. I would recommend calling Samsung to make sure you're not covered before attempting this repair yourself. If you have to do this yourself however, thanks for this ible!
nursebob3428 (author)  pstretz3 years ago
I'm glad to hear you were able to get Samsung to stand behind their product. I have to admit, given the age of my set, I didn't even think to call Samsung. There's always a risk with making assumptions!
Your observation that the original capacitors had lower values makes sense. The reports I've seen indicate the original power supply was populated with 10V max caps; the Samsung kit I purchased had 25V max caps. I would guess that's what the replacement board is populated with. As to replacing the entire board rather than just the failed capacitors, It's my guess that the cost of dropping in a replacement board (which likely costs only a few tens of dollars) is less expensive, and probably more foolproof than having someone de-soldering and replacing the failed capacitors.

bob
Never mind! I just saw the model numbers! :-)

Kudos!

K.
nursebob3428 (author)  thearchitect3 years ago
K.,

Thanks for the feedback! After reviewing what I did, I realize there are a couple of edits I want to make (adding a couple more web references on soldering, parts sources, etc.).
I wish the photos were of better quality. I've got a Canon Powershot SD30 with a crushed LCD that I've not yet repaired (I think I found the repair instructions on this site - don't quite remember); so, I was shooting "blind." So it goes... :)

Bob
Excellent instructable. If you put the model name of your TV on the title then millions of people suffering from the same issue will be able to locate your excellent work. Believe me, you will receive many thank you messages. Cheers, K.