Components for Building Computers From Scratch/Motherboard


Hi I have an Asus P5GCMX/1333 motherboard and have an issue with it. When I have a cpu in it and connect the 4 pin 12v plug the motherboard won't power up.The fan will turn once and then nothing. But when I remove the cpu  and unplug the 12v connector the motherboard will turn on and the fan stays running. I've tried different cpu's in it and a couple different power supplies but it won't run unless the cpu and plug is removed. Would you know what may be wrong? Any help is greatly appreciated.

In general the system should not be booted without CPU or power connected - of the power supplies you've tried, do they support 24-pin ATX? Are the CPUs and memory known to be working components, or are they also questionable?

If the other components going into this build are known to work, I would probably write the motherboard off as defective, however it may be the fault of the memory or CPU being incompatible or non-functioning and the board is failing to boot as a result. Ideally you would have another board/system to verify the other components as working.


Components for Building Computers From Scratch

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I have nearly two decades of experience in IT, computer repair, and related fields and will attempt to provide the most solid, brand-agnostic advice when it comes time to purchase a new computer, or upgrade an existing machine. I can answer anything from the seemingly basic to the downright complicated - and will do my best to provide this information in a clear and concise manner.


I have been an enthusiast of PC's for many years, and can answer questions about the purchase/use of a new computer or the purchase, installation, and use of upgrades for existing computers. There probably isn't a whole lot related to the home computer that I haven't seen over the years.

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