samsung ln46a550

[widgeonwing]

The tv has a squeal first time turning it on and then resets 4 or 5 times. The pic is green and very distorted at this time as well. After the 4 or 5th time of resetting, all is good and will work until it gets turned off and cools down. I've read about replacing the 102 and 131 on the power board. The problem with that is this board is not that same one. my board is a bn4400202a. i have seen a replacement board, maybe that is where the 2 caps are. I've seen the board for sale online for around $65. I can't check the 6 caps on my power board because I don't have the right meter. Should I just replace the 6 caps and go?

[sordids999]

Re: samsung ln46a550

Pictures of boards ?

[budm]

Re: samsung ln46a550

bn44-00202a is the power supply board.
C102 is on the main board not the power supply board.
https://www.badcaps.net/forum/showth...t=25810&page=7
http://www.shopjimmy.com/samsung-bn9...a550p3fxza.htm

You can try soldering 100uF 16V or 10V low ESR in parallel with C102 to see if that will solve the problem.

[widgeonwing]

Re: samsung ln46a550

oh. that would help...

[aaronwt6]

Re: samsung ln46a550

I just wanted to put a word of advice out here for both the OP as well as anyone else that runs in to these problems with the A series main boards. I've repaired 100s of these now with about a 95% success rate. I want to point out that the repair kits that are sold on both shopjimmy and other places usually contain the audio IC chip that goes on the front of the board (largest chip in the shopjimmy kit) as well as the regulator IC on the back (IC101) that goes just below C102. I have yet to have a board that needed either of those replaced. If the TV is experiencing the squealing / distorted screen, then replacing C102 and C131 is pretty much a fix 100% of the time. If the TV is continuously rebooting and playing the Samsung chime over and over but the screen never lights, then replacing C102 and C131 is about a 75% chance of repair. If the TV is rebooting over and over but no longer plays the Samsung chime then more times than not it's either got other issues or has been damaged from continued use with the bad capacitors. One's in this state I'm going to say 30% or less chance of repair with only the capacitors.

In my experience on ones I've tried to replace IC101 and IC102 on after the capacitors didn't work I have yet to come in with a success story. And unless you have an audio problem, I see no way that IC on the front needs replacing at all. This is the audio amplifier IC and if you are getting sound out of the speakers, then its functioning. It's a bear to do even with a nice hot air station. If you have no prior experience with surface mount components and the proper tools, you will almost certainly destroy the board trying to remove any of those 3 ICs. They have a giant ground / heat sink that is soldered to the the board on the bottom of the chips. Getting them off is tough and putting the new ones on straight is even harder.

Again, this is just my personal experience and recommendation based on ones I've worked on. Regardless, I'd highly suggest replacing only the two capacitors as a starting point. 95% of the time this is going to take care of the issue. If you buy a kit that contains the ICs, don't move on to those unless the capacitors fail to solve the issue.

Take

[budm]

Re: samsung ln46a550

So far c102 is the only cap I had to replace and none of the TVs come back for the same failure, and the five units that I did not replace the cap but paralleling in the cap as experiment are still working also.

[aaronwt6]

Re: samsung ln46a550

So far c102 is the only cap I had to replace and none of the TVs come back for the same failure, and the five units that I did not replace the cap but paralleling in the cap as experiment are still working also.

Agreed completely. I change C131 as well on every board I service as a precaution. I figure it's the same rating so maybe it will be next to fail. For the price of them, I just can't imagine not doing both while I'm at it. And like I said, I simply posted for the inexperienced people who may buy a kit with those ICs included; especially the audio IC that is intended to fix a completely different issue.

[widgeonwing]

Re: samsung ln46a550

You guys nailed it!!!! I replaced the 2 caps, 102 and 131 and PERFECT!!! Can't say thank you enough for all the knowledge you all have..... The soldering job is pretty rough, but all is good now..... Much appreciation to all. Dave.

[widgeonwing]

Re: samsung ln46a550

pic of fix

[budm]

Re: samsung ln46a550

Thanks for the follow-up.

[widgeonwing]

Re: samsung ln46a550

2nd chip replacement