Question Hp g60 reboot loop

Feb 4, 2020
1
0
10
Friend had an issue that she thought was power. She got a new battery and charger so I assumed that it was fixed and I offered to upgrade her hdd to an ssd. Once installed I began installing the operating system and it began rebooting. I've cleaned old thermal paste off, reapplied new paste, and cleaned all of the fans and cooling components. So I'm certain that it isnt overheating or a power issue. The only time the laptop will not reboot is when I am in the bios. Once in the bios I can leave it there for awhile with no issues, but once I exit the bios it immediately starts rebooting loop again. Am I correct in suspecting that the motherboard may be the issue? The only thing I havent really tried is poking around the motherboard with a multimeter. Any ideas?