Samsung LE46M86BD Constant Restarting

[sordids999]

Hello guys

another tv problem basically the tv comes on with picture showing but then quickly restarts and seems to be stuck in restart loop plus there is a small amount of crackling sound coming from the left speaker also im just wondering if anyone else has come against this problem

I cant even get into the service menu remote does not seem to respond with the tv also

voltages seems fine on Psu apart from them dropping once the tv restarts

Psu number BN44-00166B (had a replacement working Psu changed that still the same)

Main board number BN41-00813E BN94-01490T

Thankyou

[sordids999]

Re: Samsung LE46M86BD Constant Restarting

So i removed the heat sink and gently warmed around this area plus used a hair dryer to warm up the board and now the tv is staying on
so ill recheck this again in the morning when its cooled down

[CapLeaker]

Re: Samsung LE46M86BD Constant Restarting

there are caps underneath that cover you warmed up. So check the ones that are closest to heat first.

[sordids999]

Re: Samsung LE46M86BD Constant Restarting

Update:
changed the caps under the heat-sink tv working now so time to test

[CapLeaker]

Re: Samsung LE46M86BD Constant Restarting

A1!

[budm]

Re: Samsung LE46M86BD Constant Restarting

Nice!, so what are the caps values?
Pictures of the shield removed?

[sordids999]

Re: Samsung LE46M86BD Constant Restarting

Sorry Budm i should have took pictures but already back together i will do this
next time
i changed the two 1000UF 10 Volt caps with Panasonic 8mm radial Caps

[tuke81]

Re: Samsung LE46M86BD Constant Restarting

Just replaced those caps too on Samsung LE40R86WD telly(Same main board and those biggest ones 1000uF 10V). And it indeed fixed restart loop/warming up problem. Took couple of pics after I replaced those(Don't be too critical to my soldering skills, I haven't soldered surface mount parts for ages).

sordids999 Has it been permanent fix?

[sordids999]

Re: Samsung LE46M86BD Constant Restarting

Yes I done mine a while ago for a friend and never heard anything back yet

[Alastair E]

Re: Samsung LE46M86BD Constant Restarting

Ive done a few of those Bordeaux-Plus boards with this fault...

Sometimes, there's nothing but green lines all over screen with Hideous crackling from speakers, other times there's horizontal cogging of the picture...

With time and left on, the picture will improve, crackling go and will work OK....

[tuke81]

Re: Samsung LE46M86BD Constant Restarting

Yes I done mine a while ago for a friend and never heard anything back yet

Thank you for update. Will give this to my dad for now, he will thoroughly test it(=He is pensioner, does not do much else than watches telly).

Oh and thanks for the tip, saved me from buying new main board

[Dodgexander]

Re: Samsung LE46M86BD Constant Restarting

So i removed the heat sink and gently warmed around this area plus used a hair dryer to warm up the board and now the tv is staying on
so ill recheck this again in the morning when its cooled down

I can't believe I just found this thread, I just registered to make my own thread.

I have the 40 inch version of your TV and have a similar problem. How did you remove this heatsink? Do you have to desolder it? I don't want to force anything.

[Alastair E]

Re: Samsung LE46M86BD Constant Restarting

You have to de-solder the tinwork from the underside--They are a pain--and will need refitting once done, or the chips will overheat....

[tuke81]

Re: Samsung LE46M86BD Constant Restarting

I can't believe I just found this thread, I just registered to make my own thread.

I have the 40 inch version of your TV and have a similar problem. How did you remove this heatsink? Do you have to desolder it? I don't want to force anything.

Be sure that you fix your psu before that(secondary side electrolytic caps). Bad voltage from psu is the reason why main board is failing in the first place. Oh and be sure you have a similar problem, so use hair drier to warm up that heat sink. Restart loop should vanish quite quickly. And like Alastair said it's a pain to de-solder it, but certainly doable.

[Dodgexander]

Re: Samsung LE46M86BD Constant Restarting

You have to de-solder the tinwork from the underside--They are a pain--and will need refitting once done, or the chips will overheat....

Thanks, it was messy but I managed it.

Be sure that you fix your psu before that(secondary side electrolytic caps). Bad voltage from psu is the reason why main board is failing in the first place. Oh and be sure you have a similar problem, so use hair drier to warm up that heat sink. Restart loop should vanish quite quickly. And like Alastair said it's a pain to de-solder it, but certainly doable.

Thanks. I was kind of hoping I'd find some obvious blown caps but there's nothing. Every cap looks fine on the psu and main board. I will definitely use the hairdryer trick.

I'm not sure where to go from here, I don't own a multi meter or esr meter and have no experience on how to troubleshoot the fault.

Should I just replace the caps under the heatsink on the main board like in this thread or should I replace the caps on the psu too?

Should I invest in an esr/multi meter to test voltages and caps?

I should probably make my own thread but here is an album of my boards: https://goo.gl/photos/sAt5NG6tQ9wNpJum7

[budm]

Re: Samsung LE46M86BD Constant Restarting

Bad cap can look normal, no bulging does not mean it is good.
You should have at least Digital mulimeter and good soldering station if you want to do repair works

[Dodgexander]

Re: Samsung LE46M86BD Constant Restarting

Bad cap can look normal, no bulging does not mean it is good.
You should have at least Digital mulimeter and good soldering station if you want to do repair works

Thanks. I have a soldering station. Should I buy a multimeter and an esr meter?

[vinceroger69]

Re: Samsung LE46M86BD Constant Restarting

maybe worth changing the two capacitors as mentioned in this post and see if your set then works. I have a few meters but too be honest i use a cheap ebay esr/transitor tester more at the minute there cheap and seem too do the job ok, i only do the odd repair though if i get into repairs more i will buy bettter equiptment.
This is one of the chaeper meters some come with test leads
http://www.ebay.co.uk/itm/ESR-Tester...8AAOSwkZhWRa3K

[Dodgexander]

Re: Samsung LE46M86BD Constant Restarting

maybe worth changing the two capacitors as mentioned in this post and see if your set then works. I have a few meters but too be honest i use a cheap ebay esr/transitor tester more at the minute there cheap and seem too do the job ok, i only do the odd repair though if i get into repairs more i will buy bettter equiptment.
This is one of the chaeper meters some come with test leads
http://www.ebay.co.uk/itm/ESR-Tester...8AAOSwkZhWRa3K

I did see those and wonder, ill buy one and see.

Right now I am testing the tv, the back is off and I am trying to repeat the error.

Could you believe its now working fine? For the past few months its been flawless at turning itself off then on and now when I am sitting here testing it it won't repeat itself.

[vinceroger69]

Re: Samsung LE46M86BD Constant Restarting

Maybe when removing the cover shield the heat has made the faulty capacitors work tempory hence why we use a hair dryer to heat the boards to aid our fault finding etc a problem like this will come back and start playing up again, if your running the set without that heat shield on remember it acts as a heat sink as well for some of the chips so dont run it for long.