Repair a samsung HDTV - possible power board failure? - AVS Forum
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post #1 of 8 Old 03-30-2013, 07:44 PM - Thread Starter
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I have a 32" samsung HDTV that is not working properly that I would like to repair if possible.

The model is LN32B360 and the version is CN01.

The problem is that whenever it is on, the screen flashes on and off continuously.

If I hit it a few times on the top right corner or on the right side, it seems to temporarily fix the issue for a few minutes, but then the screen starts blinking again.

I seem to dimly recall an issue like this might be related to a failed or failing power board. However, when I took the TV apart, there are no bulging or leaking caps on the power board.

Can anyone confirm if this is the likely cause of the issue, or if there is something else going on?

Thanks smile.gif
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post #2 of 8 Old 03-31-2013, 01:43 PM
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Might just be a dirty or loose board connection hitting it is a bad idea though
could be a cold solder joint also or other things

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post #3 of 8 Old 04-03-2013, 02:43 PM
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See this thread long the fix may be simply involve cutting a jumper on the power supply board to fix " Flashlighting" issue
It a known issue with several Samsung models ,Samsung has a service bulletin that calls for simply cutting a jumper wire on the power supply board to fix it
lot of folks have fixed their own sets that way. Or had a tech do it for a minimal charge.
link:

http://www.avsforum.com/t/1340774/samsung-lcd-tv-flashing-blinking-like-a-strobe-light

this link too

forums.cnet.com/7723-13973_102-520377/samsung-ln46c630-46-lcd-flickering

videos
http://www.youtube.com/watch?v=RaLnsL4Bq_4

http://www.youtube.com/watch?v=1ZwQ0gRQ9sg


If that is does not fix it here is some more info regarding troublesooting
from a post I made at another forum
you would need a DVM to measure voltages they are usually printed on the boards at the connectors. Typically you will have 5 volt ,12 volt 24~ volt rails .

Here is good discussion with troubleshooting guides

http://www.badcaps.net/forum/showthread.php?t=25810__________________


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"The wireless music box has no commercial value. Who would pay for a message sent to nobody in particular?"

Hires Music formats ..............."Why does it sound like a CD ?" ............. "can we make it louder "?
"The wireless music box has no commercial value. Who would pay for a message sent to nobody in particular?"
- David Sarnoff's associates at RCA the 1920's -
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post #4 of 8 Old 04-05-2013, 07:18 PM - Thread Starter
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In the threads and videos you linked to, they indicated that jumper JP852 should be cut.

However, This label doesn't seem to appear on my 32" HDTV's power board.

In the linked threads, the 55" and 46" models are discussed, and the power board in my HDTV looks completely different than in the 55" and 46" models.
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post #5 of 8 Old 04-06-2013, 11:55 AM
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maybe look for a jumper that connects something
labelled 'Input rating' and another labeled 'COLD'..
looks like replacement boards are hard to come by for that set.

This is from another forum don't know the set model though but yours seems to have the same symptom
Quote:
jumper is no more than 2 cm in length. it connects something
labelled 'Input rating' and another labeled 'COLD'. the technician used
wire cutters and cut the JP852 jumper. that solved my flickering

here is an image it look like a connection to one side of AC to something called "cold" could be a floating ground trace.
Maybe your board has a similar thing
any JP 800 something or other JP numbered jumpers

Hires Music formats ..............."Why does it sound like a CD ?" ............. "can we make it louder "?
"The wireless music box has no commercial value. Who would pay for a message sent to nobody in particular?"
- David Sarnoff's associates at RCA the 1920's -
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post #6 of 8 Old 04-06-2013, 03:44 PM - Thread Starter
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There are a few JP8xx jumpers. They seem to go from JP801 up to JP837. No JP852.

There are no "cold" or "hot" labels.


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post #7 of 8 Old 04-07-2013, 05:19 PM
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here is link for a board on epay $32.95 they go as high as $ 75.00 there Shopjimmy.com is out of them.
http://www.ebay.com/itm/SAMSUNG-K02P133-00-REV-1-0-POWER-SUPLY-INVERTER-BOARD-H32HD-9AP-/230946339716?pt=US_TV_Boards_Parts_Components&hash=item35c5797b84&nma=true&si=pOK7BPKxtDjIeUEDJyop4OPXEJ8%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Board number is K02P133.00 made in China by Ampower Technology for Samsung as you already know obviously outsourced a lot of companies do that . Ampower Technology is a holding company ( hope that wasn't made on somebodys kitchen table over there) just kidding.
Supply chains aren't always that transparent.

I Googled the part # it matches up with your set model #
Google has quite a few links looks like that board is a power supply and backlight inverter combined on one board replacing it kills 2 birds with one stone so to speak so that's good.

Not knowing what the particular jumpers mentioned previously on the other sets do or exactly what circuit it is in makes it a little tough to see if there is an equivalent jumper on this board . I suspect it goes from a floating ground (neg volt rail ) to a chassis ground perhaps might be part of a soft start circuit that develops a capacitor or voltage regulator fault and shuts the board down hard to say only can guess .

Seems strange that the tech you went to mentioned a "screen control board" unusual terminology that would be more of a TCON board maybe he was thinking.

Your picture flashlighting would be the power or backlight inverter board by symptom which repairing / replacing this board should fix .

This is easily verified by voltage measurements with a DVM. duplicate symptom look for absent voltage .
You only have 3 outputs on a combined board two 5.3v rails , a 13 volt rail and a 700 volt rail the 5.3v rails probably go to the logic/tuner board and switch control board/remote receiver ,The 13 volt probably to the TCON board and the 700V rail to the lcd backlight . you can get a DVM for ~20.00 or less but if you can get a working board cheap
that;s another solution some sellers guarantee the boards power boards are the easiest to test. That board seems to be hard to find
component level repair of the board by a tech might be an option . LCD alternatives or some one may be able to repair that one.

You mentioned when you hit it the picture returns that may indicate a faulty solder joint maybe the board should be removed and all the solder joints and traces carefully inspected and re flowed as needed . Surprised the tech did not suggest that if he knew that hitting it could make it work. That would be the first thing I would look for in that circumstance aside from obviously failed parts . I wonder if he took a meter to the power supply ?
. Lead free solder they use now is not as good as the old stuff.


here is a google page on the board
http://www.google.com/webhp?source=search_app#hl=en&gs_rn=8&gs_ri=psy-ab&gs_mss=k02p133&cp=10&gs_id=1e&xhr=t&q=k02p133.00&es_nrs=true&pf=p&sclient=psy-ab&oq=k02p133.00&gs_l=&pbx=1&bav=on.2,or.r_qf.&bvm=bv.44770516,d.cGE&fp=f18f27e046486f57&biw=910&bih=423

Good luck

Hires Music formats ..............."Why does it sound like a CD ?" ............. "can we make it louder "?
"The wireless music box has no commercial value. Who would pay for a message sent to nobody in particular?"
- David Sarnoff's associates at RCA the 1920's -
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post #8 of 8 Old 12-07-2013, 09:36 PM - Thread Starter
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I had thought I responded to this eons ago, but I guess not.

Since sourcing a power board for this HDTV proved difficult, so I ended up contacting Samsung, to which they replied:
Quote:
To check and see if power boards are available, please give us a call at our J&J Parts branch at 1-800-627-4368. They are available Monday- Friday 9:00am-8:30pm Eastern standard time.

Or you can check online by following the link below:

http://www.samsungparts.com/Products/Parts_and_Accessories/LN32B360C5DXZA/Default.aspx

I ended up calling J&J and ordering over the phone, and the new power board fixed the issue.
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