Computer starts and turns off after 2 seconds. Then cycles

My system has been in storage for 3 months. I hooked it hotbox week an when I turned it on it shut down after 2 seconds. No post. After 5-6 seconds it tried to power up again but failed. It will cycle like this until I disconnect power. The case fans and ps fans turn on when I turn the computer on. The cpu fan and vc fan don't but they twitch when it powers off. I reseated the heatsink ad checked all the connections. I powered up with disconnecting the 12v atx to the mobo. It started but with no CPU running obviously. Any suggestions?
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More about computer starts turns seconds cycles
  1. Gigabyte ga-ep45-ud3r
    I think e7300
    Corsair 450
    Sapphire 4850
    4 gig g skill ddr2 800
  2. well since you checkd all the connections already , try resetting the mobo cmos battery by removing it and reseating after a few minutes. a similar situation happened to me on a pc i was repairing and my suggestion worked for me.

    RSL1989 build:
    -MSI P67A-G45 (B3) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
    -Intel Core i5-2500K Sandy Bridge 3.3GHz @4.0 OC Quad-Core Processor
    -ASUS ENGTX550 TI DC TOP/DI/1GD5 GeForce GTX 550 Ti (Fermi) 1GB 192-bit GDDR5
    -Seagate Barracuda ST31000524AS 1TB 7200 RPM SATA 6.0Gb/s / -LITE-ON DVD Burner 24X
    -G.SKILL Ripjaws Series 8GB (2 x 4GB) DDR3 SDRAM DDR3 1600 (PC3 12800)
    -Rosewill RV2-700 700W ATX12V SLI ready / -Rosewill FUTURE Gaming ATX Mid Case
    -Sunbeam RHK-BA Rheobus 4 Channel 20W Fan Controller Panel / -6 Rosewill 120mm Blue LED Fans
  3. I did reset CMOS and it still hasn't worked. From what I've read it sounds like the shutting down is a safety issue for overheating CPU but I hardly think it would overheat in 2 seconds. I thought maybe the ps was bad but the fan still runs and I tested some ofthe other connections and they worked. I'm thinking maybe the mobo or CPU is bad...
  4. Some mobos will shut the system down immediately if they start the power up cycle and do not detect that the cooler fan is spinning. So that's one place to look. They sense the rpm via wire 3 of the 3- or 4- pin connector from the fan to the mobo. Check if the fan is spinning and perhaps r/r the connector cleaning the mobo pins.
  5. I've tried everything I can think of and all suggestions on got on here. It still won't work....
  6. I had a Dell system with similar symptoms once . . . if I manually spun the cpu cooler fan almost immediately after pressing the case power switch the system would start up and the cpu fan would continue spinning on its own.

    You could also try connecting one of your case fans (if its 3-pin) to the cpu fan socket. If a bad fan is preventing BIOS from starting up, this would fool it into thinking all was ok. Obviously, it won't cool your cpu though :)

    If I had a spare psu, I'd swap it in and see if that's the problem. If its not the cooler fan or psu, the next candidate in line would seem to be the mobo.
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