Samsung LCD TV LA40R71BD won't power on D.I.Y. Review!
Seems there is a problem with some power supplies on several Samsung Flat Panel LCD TV models.
I first noticed it taking longer to power on with the relay clicking more and more, taking longer and longer to see a picture.
It would have failed completely, no doubt but I was already frustrated waiting 5 min to see the news I just missed!
Others have done the same as me so this review / fix is simply how I went about it.
You can source replacement power boards, generally in the $100 range. A serviceman may charge say $200.
The $4.56 repair.
DIY (Worth a try, can always buy a new PCB if it's a failure) - This is at your own risk. Allow 2 hours. Don't even think of blaming me if it turns to crap. Please if you have no idea about electronics call Samsung.
It looks to me as if there was a batch of faulty capacitors else they are under rated for the job. You can tell they are failing as the tops expand. There are 4 the same so I replaced them all, even if one looked OK.
I opted for 16V not 10V as fitted. (Total cost $4.56) You can go higher voltage no problems, but you need 1,000uF (micro-farads) a few more uF should be OK but 1,000 is fairly easy to source. (I got mine from Radio Parts Group, Dick may have some or any electronics kit store)
You will need:
Solder Wick or Sucker, Solder, Soldering Iron, Cutters..
(If you have to buy the above you'll be up for about $50 in total)
And don't forget the star of the show..
4 x 16v 1,000uF Capacitors = $4.56.
You'll also need a Phillips head screwdriver to remove the back panel, it comes off easily ONCE you find all the screws. I put my TV face down on the bed.
UNPLUG THE POWER - Dead people don't watch TV.
Remove the back panel, locate the Power PCB (See below) unplug all connections (most have catches you push in to release) then remove the 6 screws holding the board.
(Area marked is where the lazy capacitors hang out)
Four Capacitors Location:
Warning one cap is reversed
(The one on the right in this image..)
To remove the old capacitors. I found the solder wick fairly useless with my 25W soldering iron but I didn't want to use too much heat and cook the board.
I heated each leg of the old caps and kept moving the cap while the solder cooled, this creates a "dry joint" and you can pull the cap like a tooth easily, leaving a hole for the new cap's lead. You can try solder wick (50w iron needed?) I found heating the joints while moving the caps got them out and left a nice lead hole. There is a fine line between mastery and butchery here.
Solder in the new caps, get the solder HOT else you could end up with a dry joint that you don't want. Use the cutters to trim the legs.
Reinstall the board, double check all connections. You could test it before you put the case back on, that way you're ready for plan B.. It worked for me.
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