My current computer is a Dell Studio XPS 435. It's seven years old this month. It's been essentially trouble free until maybe a month ago when it started "acting up"..just as you described.
Locking Up seems to be the predominate problem...power fluctuations..going from a normal 147-153 watts up to as high as 210-240 watts. (Includes monitor) My Cyber Power battery backup has a real time power consumption LCD display. Power goes up..the fan ramps up..then lock up.
EDIT: If they send me the TV, I think I'll give it to the Senior Center up the road from me.
