I desperately need help. I just upgraded my CPU from a i5 6600 to an i5 8400 but my pc does not boot up. Everything will turn on for a split second (like fans and lights) but then will immediately switch off, there is also a red light that turns on next to the words cpu. The motherboard is a MSI H110M gaming motherboard. I have tried to troubleshoot it buy cant get it right, i have also put the old cpu back in and it actually does boot up. I dont know what else to do. Could it be a faulty cpu?