I have just built a new computer using an Asus PH61-M LX motherboard and Intel i5 3450 CPU and 8 GB DDR3 Ram. I am unable to start it up. Power comes on and immediately switches off and tries to restart. Unable to even get into the bios. Have stried connecting a new Power Supply without any change and do not know where to go from here.
Finally figured it out. Motherboard is older than the Processor and does not recognize it.
Fixed by installing older processor and flassing the bios and then reinstalling the original processor. Worked like a charm.