Computer Start Up Problem

[IfYouHaveToAsk]

Ok my PC is just under a year old and has no problems apart from this. When i boot up after the computers been off all night all that happens is you can hear the fans spinning really loud, and its reading the hdd and cd drive and the monitor stays black. However if i turn off the power at the back of the pc then turn it back on it works fine.

This only happens if the PC has been off over night, if its only been off an hour or so then this doesnt happen and the pc boots first time.

Any help would be appreciated.

 

[Nitestick]

try replacing the CMOS battery.

 

[IfYouHaveToAsk]

is that replace as in take it out for a few minutes then put it back or buy a new one?

 

[Nitestick]

well try both perhaps. i did mean purchase a new battery though

 

[IfYouHaveToAsk]

ok well i turned the pc off for about 1-2hours and it did the same thing, so i opened up the case and discovered that the graphics card fan was the one that was making the noise.

i then blew away any dust i could see (there wasnt that much since i cleaned it last month) and reseated the graphics card. i put the power back on at the mains (i had it turned off at the mains whilst i opened it up) and it booted first time. So i turned it off again and left it for 5 minutes and it again booted up fine.

it seems a bit strange that it only has trouble when its been left off for an hour or more. hopefully it was just some dust or something trivial and the problem is solved but if it doesnt boot up first time tomorrow morning after its been off at night then i'll tell you.

im just confused how a) there are no other problems with the pc (ruling out many things) b) the graphics card fan becomes excessively loud when the pc doesnt boot and c) how come the problem is solved if i just replug the mains at the wall (or the switch at the back of the psu)

hopefully i've sorted it out but if not theres some things for you lot to think about.

p.s i havent tried resetting cmos yet but if it happens again i will try.