Upgrade package installed - Computer no longer works

[Mortac]

I just put in a new mobo, CPU, RAM, video card and harddrive. When I turn on the computer it starts up in a really odd way. The fans begin to speed up as normal only to turn off briefly (probably half a sec or less) and then begin to speed up again. It does this repeatedly until I turn off my computer by holding the power button for a while. Both the power LED and the LEDs on the video card blink repeatedly as well (probably because of the constant turning on). So it appears to me that the computer tries to turn on only to have it fail somewhere, so it shuts off power to the parts such as fans very briefly, only to try to turn on again. This goes on until I turn off by holding the power button for a while. Oh, and I get nothing on the screen.

Any ideas? I was really excited to receive the new parts and now that it didn't work properly it's quite a pain.

The computer:
Seasonic S12 600W
AMD Phenom II X3 720 BE 2,8GHz Box
Gigabyte GA-MA790XT-UD4P
640GB Western Digital Caviar Black
OCZ Reaper HPC DDR3 1333MHz 4GB Kit
Sapphire Radeon HD4890

Everything but the PSU are new parts.

Any ideas would be most welcome.

 

[Mortac]

Alright so I have tried the following without result:

I have changed video card and monitor.
I have tried running with one memory module and moving it around into different slots.
I have tried running without HDD and DVD.
I have tried reconnecting different cables.
I have tried resetting the BIOS by taking out the battery. After this, it appear I can no longer shut off the PC by holding the power button.

When I changed the video card, the fans no longer "restart" their spinning every few seconds as they now spin smoothly once I turn the computer on. The HDD led in the front of my case blink every 3 seconds or so, and this is no matter if I have the SATA and power cables connected to the HDD or not.

I'm running out of ideas here guys. I sure hope nothing's broken.

 

[Mortac]

Well, incase someone with similar problems ever reads this: I solved it by remounting the CPU and its cooler. Apparently something was not completely right there.

 

[mpilchfamily]

Yes if the CPU wasn't installed right you could run into this kind of a problem. It could also be a DOA motherboard.

 

[Swampster]

If you cooler didn't have an appropriate application of thermal paste, or if it was not mounted flush, this would be the result.

When you first start a computer, it checks to see if you have an operable fan connected to the CPU Fan Header. If so, then it starts monitoring the temps and checking everything else.

In your case, what likely was happening was that it saw the fan, so it continues, but the temperature spiked because of lack of heat transfer (cooler slightly cocked), so it shut down. Temps can drop almost as fast as they go up, do it was probably going below the threshhold and then bouncing back and forth.

You are fortunate that you didn't fry the CPU while you were trying to figure it out. At this point, stay away from any overclocking, and watch it closely over the next few months for erratic and oddball problems, as this would be a sign of a damaged CPU.

Good Luck.