I've got a four year old Macbook Pro 17", running 10.5.8 OSC, 2.33 ghz, 3gb 667 mhz ddr2 sdram. The power cord was unplugged, although the battery was fully charged. I plugged in my Canon printer for the first time in over a year. It printed half a document, then the computer shut down. I pushed the power button and got the start up chord, but then it shut down again. Tried this a few times. Then I unplugged the printer and plugged in the power chord. it started, but it's very slow, and I keep getting the pinwheel. Is there any diagnostic I can run?