cheking nvrame hangs or stuck


Most motherboards have the CPU fan protection, if the boot failed to detect the speed of the fan power supply or fan, it will not boot, then the motherboard has power, CPU is normal hot things, (of course, not all protection of the motherboard CPU all of this, some CPU power is not.) CPU can be hot, but also prove that the work of CPU time, the replacement of the fan should be able to solve. 
In some special cases, we determine whether the CPU has been burned, but also specifically the fan removed, a hand to detect CPU temperature