Thanks, but I have cleaned the laptop several times, over the years. The thermal pads have all been replaced by thermal pads by Akasa, thermal paste has been Thermalright Chill factor III for roughly the last year. The temp monitor in the Nvidia Settings manager has never reached alarming values (it was like 80 Celsius, and only when at load). And it does not seem to explain the problems with Memtest86+ as described in the OP, nor the unresponsive keyboard/touchpad. I could try your suggestion though. So people have suggested the following: - get a (cheap) stick of RAM to verify the working of the RAM and DIMMs - get another power brick - improve the GPU VRAM cooling drastically, somehow. @CaptainFailcon: you posted before I posted this so I had to edit to add the quote for clarity.