Check these posts out:
Problem: screen is flashing on all imputsSolution: some LN46C630K1F have a faulty jumper switch. Specifically Jumper 852 should be cut and removed per Samsung.This
is a Samsung fix according to the Geek Squad with Best Buy. However,
if you do not have this problem until after you have owned for 12 months
Samsung assumes no liability and will not pay for repair or reimburse
for repaid. This is despite knowing the problem and how to fix.Very un-Samsung based on previous experience and not like Best Buy to stand by and do nothing.
Woohoo!! Easy fix!! by chawnskie - 11/14/11 8:37 PM In Reply to: Me too (3): LN46C630 Flickering by chawnskie I continued my Google search after posting here. I found the below post on the Amazon forum:<i>" Denise says: i have the LN46C630 model with same flickering problem occuring just after warranty expired. technician fixed it by cutting one "jumper" (metal wire about 1/2 inch long) located on the power supply circuit board. takes 5 minutes to fix. technician said samsung issued service bulletin that told repair techs how to fix it. you can do it yourself with
a screwdriver, small wirecutters. i could send a photo if you wantok,
not sure how to post the photo here, but here's what the technician did
for $150...unscrew 17 screws, remove the back cover to the TVfind the power supply circuit board, that's the one your TV's power cord plugs into. On the power supply circuit board, upper left corner, to the right of and below the large 46", there is a metal jumper labelled JP852 that 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 issue, TV works great now. tech said that every size TV in this class of samsung has the same design flaw and can be fixed like this. good luck. i would post a photo, but can't figure it out."</i>source: http://www.amazon.com/review/R1PD14XKZ7MKCZ/ref=cm_srch_res_rtr_alt_4It
works. I can hardly believe it, but my TV went from a complete black
screen after a few minutes of flickering, to good as new with the clip
of a tiny wire!!! It took ~ 15mins to complete. I thought for sure it
was one of those "too good to be true" moments, but since I was assuming
I wouldn't get warranty support, I figured why not. When has the
internet last led me astray...? Ok, we won't talk about that Samsung_HD_Tech,
any chance you could inquire within and let us know what this does? The
post says there was a service bulletin. If so, they know about it.This
seems like a solution for a lot of people who are out of warranty or
don't want to deal with the hassle of service even if under warranty. Next unread
spudsdude12-23-11, 12:03 PMWow, talk about a fix that should be public.
Cut a jumper they missed at the factory. JP852 on the power supply board.
The fix (for backlight strobing):
Remove phillips screws that hold the back black metal cover onto the tv,
there's one screw at the inputs area, the rest are all around the
outside of the frame. All are in plain sight and no stickers or other
items have to be removed to get the cover off.
After you have the cover off, cut a jumper on the power supply board that was missed at the factory.
Jumper location: JP852, it's a small connecting wire between the input and cold area of the power supply board.
There's a Samsung bulletin for this issue, it didn't show up on the
repair guys computer. He called them as he thought it could be the panel
itself (which requires authorization as it's over some set value), the
guy on the line said it's a known issue and there was a bulletin by
While I didn't get the bulletin number, the fix is to cut a jumper on
the power supply board, something they missed in the factory.
He cut that jumper, put the back panel back on and remounted the tv (it's wall mounted), problem fixed.
The repair guy said every Samsung TV in this class has the same issue,
something that was missed at the factory. In my opinion this should be
public knowledge and Samsung should be fixing these for free, even for
those out of warranty.
A quick google search on the jumper lead me to another thread, with another model that was affected by this issue LN46C630
I also asked about a "buddy's older Samsung TV", thinking of the guy in
this thread that said his TV takes forever to turn on, he said that's
another known issue with bad cap's on the power supply, easily seen by
bulging of the cap's. To fix those the caps have to be replaced, he said
that's so common that he keeps a whole bunch of caps for the Samsung
power supply's in his repair truck.
not sure if it works and a little worried about cutting a jumper but I have the same issues....