I also have this problem with my n3250w - ANY input (PC, tuner, A/V,
etc.) will just quit after 1-2 hours.

The audio pops, the screen goes blank, and the remote will not work.
Only turning the unit off at the set button, then turning it back on
works (only for an hour or so more, then repeat).

It seems like it's overheating or something. Anyone have any ideas?

I can confirm that this problem is NOT power management.

-Sean