Samsung LE40F86 switching off and on automatically like a reboot


Active Member
I have only owned this television for about 1 week now, so am still learning about it. However I have found this problem during an evening of watching TV.

Has anyone experienced while watching the TV it switch off and then back on again after a few seconds.
It is the exact same operation as if i'd pressed the on/off button but happening without any intervention.
It has only happen 2x over the last 3 days, but is rather strange and rather annoying while in the middle of watching a dvd.]

I can hear what I presume is the relay clicking for it to switch off, then the lights go out on right, followed by them lighting up 1 at a time as they do when you turn the TV back on again.

Do I need to get it replaced? Is it a "new TV" problem and automatically settles down, or is it a simple firmware patch some engineer can come out and sort.

Thank you in advance



I have had this problem twice now an I'm on my 3rd Samsung LE40F86-HT TV. My 1st one developed the on and off problem you described very quickly, an engineer came out and said it was a power supply problem, it was returned and exchanged for a new one. The 2nd TV sufferred from green parellel lines through the TV which was described by the same engineer (I even remembered that he didn't take suger, it was so close to his last visit) said it was the main board that went wrong, the TV was changed again and we are now on our 3rd TV, 4 months since getting it and the on/off problem has started again. I'm contacting Comets today and feel sick that I have to go through this again. The original TV was purchased 10th November 2007 it was returned to the store by 17th December.
I hope this helps you decide to take your TV back, our on/off problem got progressively worse.

Good luck with yours


Active Member
Thank you for the reply (and welcome to the forum too :p)
That is not the news I hoped to hear, (was secretly hoping it "settles down") but will have to consider that now as an option.

THe pain is that I bought the TV through Empire Direct so I have the issue of returning to an internet company. It's so much easier just to goto Comet and stand at their desk and make a fuss.

Anyway, shall see how things go with it. I've thought about the power supply issue and have plugged it into a surge protector as wondered if that may help a little.
Too early to say, not noticed any significant difference in performance either way.

Anyone else have experiences with this issue?


Active Member
Hmmm double posting, that's not good.. oh well.

Anyway, It's been some time since I had this problem (touch wood) so thought i'd share my findings to date.

Turn off energy saving if you have it switched on
Unplug the TV from the wall and leave it for at least 4 hours.

The general consensus seems to be a slight power surge/spike probably causes it and it was simply protecting it's self.

Anyway, decided I did not want the TV protecting it's self so i've bought a surge protector for the TV and plugged all the other electricals into it while at it.

Hope that helps if you are experiencing similar to me.

PS this is not an easy topic to google on by the way hee hee.

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