Samsung LN46A650A1F easy fix

[budm]

This 2008 Samsung 46" came in yesterday. Bad caps, of course.
More pictures here:
http://s807.photobucket.com/user/bud...?sort=3&page=1
So far no tab bond problem showing up yet either.

[tom66]

Re: Samsung LN46A650A1F easy fix

Nice. I've had the LE40A656 with bad caps, and I stuck it in the front room at parents house... still going fine, no tab bond issue either.
Did you replace all the caps? I did all on mine with Panasonic FR and FC.

[budm]

Re: Samsung LN46A650A1F easy fix

Yes, I replaced the 2 bad one first to see if I can get the backlights to come on first to make sure it does not have cracked screen, I replace the set of caps after the verification.

[tom66]

Re: Samsung LN46A650A1F easy fix

I'd imagine you could still pull the power board cable to do the backlight check, even if caps are bad? After all inverter is primary side. Not sure how dependent it is on the power supply working OK, or if this model supports that test.

[budm]

Re: Samsung LN46A650A1F easy fix

That is what I did first but that did not work, It is the bad caps in the power supply (stby ps) is not supplying the pull up voltage to turn the PS_ON and the BL_ON signal, after new caps installed the backlights come out with the cable disconnected between the power supply and the main board.
When I first turn on the TV before repairing, it was going on and off with Samsung chime, stuck in that mode.

[tom66]

Re: Samsung LN46A650A1F easy fix

Or maybe inverter control circuit runs off 13V rail. Not sure if it is separate rail or shared.
I see Samsung did not bother with fan for cooling the motion FRC on t-con on this model. The t-con on one I did failed even with that fan blowing air over it.

[tibimakai]

Re: Samsung LN46A650A1F easy fix

I have the same exact TV and after replacing all the capacitors(except the two large ones), it's working for a while and then the backlight shuts down, but everything else it's still working.

[tom66]

Re: Samsung LN46A650A1F easy fix

You should probably start a thread if you haven't already.

[tibimakai]

Re: Samsung LN46A650A1F easy fix

I have one already.

[budm]

Re: Samsung LN46A650A1F easy fix

Look at the FB and LD signal.
LD = 10~12V
FB = 0 V

[tibimakai]

Re: Samsung LN46A650A1F easy fix

I will look for that. Thanks. It's so hot in the garage, that it may take a while until I will get back.
Here is my thread:
https://www.badcaps.net/forum/showth...hlight=samsung
I think that it's not a good idea to run the TV without the back metal cover. I keep a fan over those boards while I'm waiting for the backlights to turn off.
Because of the heat, I slowed down on TV repair and trying to repair Kenwood double din units, with not much success. I'm not getting any help in the audio forum.

[tibimakai]

Re: Samsung LN46A650A1F easy fix

Actually, I have that info already in my other thread, post #11.

[tom66]

Re: Samsung LN46A650A1F easy fix

The metal cover is only for EMI. i.e. you could annoy the HAMs by leaving it off, but it won't affect the TV's operation.