Keeps turning itself off with a red light next to

Probably something wrong with the lamp. Buy a replacement.

it is def. the lamp. I have the same tv

If the second light is blinking to orange or red, that is usually the lamp indicator light on an LG DLP tv. That indicates your bulb needs replaced, or something surrounding the bulb has failed (like the cooling fan for the bulb for example) IF you have a spare bulb handy, I'd replace the bulb, keeping in mind if you touch any part of a new bulb with your bare hands, you just cut the life of the bulb by more then half.

Go to a repair centre, some parts must be fixed/replaced.

Probably easily fixed the protection circuit is kicking in. ie something is wrong with the power supply or something it supplies is not giving the correct feedback. If you press the remote does the led flash on the tv. If so it is trying to power up. You could open it up if you are electricly safe. And have a look at the condition of the components. Leave it for a while and it may come on on its own a while being 15 mins

solder bad connections on power supply pcb.......T.

you have mention that after 10-15 seconds T.V starts up, will you give total description of the T.V within that 10-15 seconds?

42 inch Toshiba DLP. Was watching a movie and the screen went dark. The red light started to flash and kept flashing. any ideas 

the tv will try to reboot a few times. just let i try and eventually it will start blinking red. if you could count the red blinks then i can further assist you.