Do you think that its heat related? If you are fmiliar with the inside parts of the laptop then you could redo the compound between the CPU and heat sink. Clean fans, etc. While your at it redo any heat sink that can be done with heat sink compound, such as GPU etc. If any are glued then don' force, ignore. Clean all dust thouroughly. You can wash plastic parts and filters with soap and water... Be thorough. If problem persists and you are desperate then you can google "reball HP ENVY"... If it is heat related please fix it before using the device or you can exacerbate any damage.