It was a heat issue. Short of fixing it, go to the power control settings and tell it to run at the low power saving speed while on AC power.
But it usually can be fixed by shops like ikenfixit.com or notefix.com for much less than a new laptop. After that you put it on a laptop cooling pad.
I didn't mention cleaning out the vents and heatsinks which is "preventitive maintenance."
My laptop will only run when it is NOT receiving external power. I can plug it in while it is off and the battery will charge. If I then unplug it from the wall, it will boot up and run just fine until battery power runs out. But if at any point I plug it in, it will restart and then continuously crash while still attached to an external power source. Any ideas? Thanks much!