I have a Toshiba laptop that suufers tyhe same symtoms when my wife uses it on her lap with a blanket. I think it is certainly heat related. When it shuts down I take it and hold it in front of my fan for a ouple of minutes and scold the wife and it works fine. keep it cool and there should be no problem.

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1983 300 SD 149k

1983 300 D 280k

1980 vw rabbit 1.5 na

1965 356C