When I was 'repairing' peoples old laptops, the biggest intermittent problem by far, (2nd to the ubiquitous Viruses etc...), was
old dried out Heat-Sink paste!!! causing them to thermally shut down. Modern laptops can run so hot, as they are 'pushed' so
far these days. Oh... I tell a partial lie... And education of laptop 'users' to NOT leave their laptop on top of their Doona/quilt when
in bed!!! The damn intake air is usually underneath, and gets totally blocked!!!