shuts off then wont turn on for a while

grasshopper645

New Member
Messages
3
As title says, computer randomly shut off without warning and won't turn back on. However if I wait for a while or reset the bios by removing the battery it will then decide to start again. It seems to occur when I am putting decent load on the system, and will always happen after about ten minutes of running prime95.

My initial thoughts are overheating however monitoring with core temp the CPU never goes above 65 degrees. Another weird thing is after the shutdown the bios will reset by itself if I wait. I tested the PSU with a multimeter and the voltages are fine. I'm thinking PSU, CPU or mobo. What are your thoughts?
 

My Computer

System One

  • OS
    Windows 8 Pro
    CPU
    Core i5 650
    Motherboard
    Gigabyte h55m
    Memory
    4gb ddr3
Another strange thing I've noticed. If I plug the CPU fan into the CPU fan connector on the motherboard the system overheats when under load. As the CPU heats up the fan seems to slow down. Starting at about 1100rpm and slowing to about 600rpm as the CPU overheats. I shut it off at 80 to prevent damage. I tried all the different fan settings - pwm, voltage and running at max all with the same result.

If i plug the fan directly into the PSU it doesn't overheat, but system still shuts off.

Im not sure what to do! Don't want to start replacing parts if I don't know what the problem is.
 

My Computer

System One

  • OS
    Windows 8 Pro
    CPU
    Core i5 650
    Motherboard
    Gigabyte h55m
    Memory
    4gb ddr3
Back
Top