SAMSUNG TV MODEL HLR5067W

I have a few friends in the UK with the very same TV and no problem at all.
I would suspect either a power supply fault or a bad connection somewhere and I would return it for a replacement.

Replace the power supply, PN: BN44-00206A

It's easy to locate, but requires adjustments once it is installed. Panel voltages must be adjusted according the the specifications of the TV. There is a sticker on the back of the plasma panel which provides each voltage setting. You can reference this sticker to make the proper adjustment. Using a DMM, connected between chassis ground and the panel voltage you are adjusting, turn the adjustments on the power supply very slowly, until you are measuring the specified voltage within 0.5v. I hope this helps and good luck.

first of all let me ask how old is the battery, if it`s new-discharge the battery until pc shuts down itself because of low battery, remove the battery , unplug AC charger from laptop, wait for 5 minutes, then hold power button for 5 full seconds, wait another 5 minutes, then put battery and ac charger on , don`t turn on laptop yet, wait until battery indicator shows that battery fully charged, then remove AC charger, and turn on laptop. P.S. you can try this on old battery too, but usually worthless, because old batteries are not recognizable by system currectly ..

I would suspect the lamp first as they can cause intermittent shut down issues.

move the speaker away from the tv

what i would do is crack into the tv and watch the individual parts being careful not to unplug anything while you take the back panel off.....turn it on and see what happens. let me know what happens

what is the model # and brand

Sounds like the lamp to me. The projection lamps get hotter as they age and the TVs have a sensor to monitor the temp and shutdown the TV if it get too high
Projection TV makers charge an arm and a leg for their replacement lamps. They make it easy to do but as a result the custom lamp assy is expensive. The trick is to buy just the bulb for your model TV from any number of us aftermarket sources at a fraction of the lamp price and install it in the old lamp yourself. Really easy.