I'd try reading http://www.tomshardware.com/reviews/thermal-paste-performance-benchmark,3616.html but let's at least read you used Arctic Pro or such.
Next laptops can get old and get hotter. The DV6 looks to be beyond the normal service life and should barely game on.
So, try the best paste you can get and put it on a cooling pad.
I have an HP DV6-2020CA laptop, with AMD processor and graphics. For some reason the laptop keeps overheating. I have taken it apart and adjusted the heatsink and cooling system many times, to no success. When I turn it on, the computer's fan spins at full speed, and then, just after Windows finishes loading, it shuts off from overheating. The heat sink makes contact with the processor and graphics chip and there is thermal paste. Does anyone know why this keeps happening and how to fix it?

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