Computer sometimes doesn't boot (stalls/odd fan noise)

[Mr Bob]

I have two issues here, both happen on a cold boot, and both don't happen everytime. Computer is the one in the sig, without the hardcano installed.

1) When the windows loading screen comes up (with the black background), it only gets about 2-3 frames and freezes. This usually happens on a cold boot.
2) When I turn on the computer, my CPU fan makes a HUGE increase in sound, about 50 times than what it should be. When I move around the video card a tad (just push it in or barely apply any pressure to it, the noise of the fan decreases a lot. After a few restarts it finally goes away.

Any ideas on this one?

 

[Jiggz]

There is a saying "When the problem starts only at start up and eventually goes away, or goes away by tapping or moving the uni, the source is most likely mechanical". So you might want to check all your connections and also add in cards. Don't forget about the mobo installation also. If the problem does not go away, then disconnect all peripherals including the OS hdd. Just leave the mobo, kb, mouse, ram, video card and re-start the system. Is the fan still making noise? If the noise goes away (after a couple of tests). Shut down and re-connect the OS hdd. Reboot. Did the system freeze? Is the fan making noise? If the system boots alright, continue re-connecting the peripherals one at a time while testing along the way. As soon as the problem arises when you re-connect a peripheral. Try re-connecting that peripheral first right after the OS HDD. If the problem of freezing is still present, the peripheral is faulty. If the problem won't go away after an increase of peripherals connected, the PSU is having problems with high loads.

 

[Mr Bob]

Thanks Jiggz. But how could a PSU problem cause a fan to increase in noise level?

 

[Mr Bob]

bump

 

[bigpow]

The fan noise may or may not related to the windows stuck too long at boot screen.
Try disabling USB Keyboard/storage support from BIOS, see if that helps - that was a bug with my Neo4 SLI.

As for the fan noise, try replacing the fan