not sure about this but.. isn't 70C pretty much a temp that will cook your CPU!! .. it really does sound like you fried it

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8 MHz Intel 8088 Processor
20MB IBM hard drive
PIM-TB10-Z 10 MHz Turbo Mainboard with 27256 ROM BASIC chip
MG-150 Monographics Card with parallel port
Samsung MD-1278G 12" monochrome monitor
Epson FX86E 9-pin dot matrix printer
Keytronics 101-key keyboard (Enhanced AT-style)