Have a 4 year old Samsung HLN567W. No problems over the years, except for lamp replacement issues (replaced the lamp late last year as OEM lamp was nearly end of life and replacement lamp broke after 5 months; newest lamp now in for 4 months and working good so far). About 3 weeks ago, the TV began spontaneously turning itself off periodically. Has happened about 5 times now over this time period. We would be watching TV and the screen suddenly goes out (beeps and flashes the green light in the bezel just like normal shut down). When I start it back up, comes right back up normally as if nothing ever happened. It is on a powerstrip that has several other A/V components and they were unaffected. Last week I decided to change out the power strip (as it was getting old and living in Florida power surges from lighting is an issue) and plugged the new power strip into the adjacent electrical socket. Thought the problem was fixed as it didn't happen for a week, but then it happened again yesterday morning.

Any thoughts as to what may be happening here?

Could it be overheating? Did you try to clean out the inside areas around the bulb and fans when you replaced the bulb. Also, vacuum all the external vent areas to remove any dust. I'm only guessing but these tvs are like computers which need a good dust removal after a while.

Ok, thanks. I will try this, then. I assume my carpet vacum with the brush attachment would work?

I used my carpet vacuum for the exterior vent cleaning without any attachment, but as long as it doesn't have a bunch of dust on the attachment, it should be fine.

I haven't cleaned the inside of mine yet as I haven't changed the bulb yet, but I have a special computer cleaning attachment set which reduces the suction of a normal vacuum for when I clean my computer and that's what I would use inside. You don't want much dust movement inside and the smaller tools in the computer cleaning kit help get inside without hitting anything vital and reduce the suction so you don't accidently suction something out.

If you can, post back if this helps so I'll know when I change my bulb how much cleaning to do. Thanks.

It could be the lamp ballast going bad.

Mes - thanks. i will try this and tell you how it goes.

Waldorf -- what exactly is the lamp "ballast"?

mes -- nothing much to the cleaning. wasn't really that dusty inside. not sure how good of a job i did but my vacum is one of those strong dysons and so i didn't want to poke around too much. one thing i noticed is that the TV was very close to the wall and i could feel the heat from the TV reflecting off the wall big time. this turning off problem began shortly after we returned from a weeklong trip to the Florida Keys where we spend a lot of time outside. when we got back, i put the house thermostat up a couple of degrees from where it was prior as it felt cold inside. this being the hottest time of the year, i am wondering if perhaps this was just enough to trigger the high temp shut off saftey feature on the TV. so far, it has not shut down since i pulled away from the wall some. we'll see if perhaps that was the problem.

Sounds promising. Keep us posted. Nice to know they don't get too dusty.

Maybe this HLN service manual will help....
http://www.evstar.eatsleepcode.ca/HLN_Manual/