Samsung model LTN1535-S Problem intermittent. Operates well for several minutes to several hours, then shuts down . Restart by pressing power button.

It ran out of battery. Put it on charge. Wait 30 minutes.

Press and hold Power Button and Volume up Button until you see the Recovery Console. Choose Restart.

Samsung Galaxy E7: How to restart when hanged:

Since the battery on this particular phone is not removable, you can try holding down the power button until it auto shuts down.. it may take 1-2 minutes. Once it shuts down, let go of the power button. Then press the power button like normal to turn it back on.

things that happen to older laptops are that over time there tiny processor power supplies build up with lint from the air that is passed thru them sometimes even making the tiny cooling fans in there stop , then its only a matter of a few minutes and it overheats and shuts off , after several hours cool own it will restart , but wont stay on long , then the cycle repeats . if its caught in time and no power supply parts are ruined sometimes a Pc repair shop can dismantle one and clean it

DVD mechanism fault.

Have to start at the beginning---Lamp? Ballast? Color wheel?

Unplug the computer for a minute and plug it back in. It should restart normally.

Usually you restart just by tapping a key in sleep or hitting the power in hibernate.

go into the menu to find out the lamp hours. it could be the lamp, but if the projector shuts down and not just the lamp, there is either an overheating issue, or a power supply issue.

You may have a low pressure or high pressure switch tripping out the board as well. You might try cleaning both the indoor (evaporator) coil and the outdoor (condensing) coil. Be sure to turn off the power source before servicing this.

OTHERWISE- THIS SET MAY HAVE THE DREADED 1500UF POWER CAPACITOR ISSUE WHICH ARE EASY TO SEE IF YOU CAN ACCESS THE MAIN POWER PC AND VISUALLY CHECK FOR 'POPPED' CAPACITORS ON THAT PC. JOE TV

does the main board have the flyback on it? if so the yokes or CRTs can be intermittently shorting which in turn triggers your shut-down.
turning it off or unplugging just resets the shut down circuit.