Operating system bootup screen freeze, IT guy says it is the CPU

I spilled some water on my hp elitebook 8460p. after I left the laptop for couple of hours the laptop used to only show keyboard lights when power on then after using reset keyboard shortcut it booted till grub menu and freezes and eventually was completely black (no reaction to power on, only charger led was on).

The IT gut first told me that part of the motherboard had power issue and changed some ICs. now the computer boots bios but freezes while loading OS (after selecting OS from grub menu) the IT guy now says it is a CPU problem (mine is i7-2520M) because when he tested another cpu it boots normally and when he tested my cpu on another hp 8460p, it had the same problem.

AFAIK during the boot up process bios is loaded by the cpu, so at least my cpu starts normally and boots bios. What can be the problem (I mean in the CPU)? is there a health test method to know what is the problem exactly with my CPU?