Computer not booting

jenic

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My new PC which i have custom built is not booting with the case side on, i have checked that the case is not trapping anything and it isnt. I have not got the case light connected and it still only boots with the side off.

I have decided that the only possible thing must be cooling but the air from the heatsink is cool and when i open the case there is no noticeable heat. This started happening around 40mins ago.

Any advice is very gratefully recieved.
 
Is there anyway (unlikely I know but you have an unlikely error!) that putting the case on could cause the mobo or a.n.other wire connection to be touching metal where its not supposed to be?

I once had a situation where I had not used all the screw points putting in a mobo and, because of this I guess one of the strips/lanes of the mobo was touching metal case where it was not supposed to. This caused it not to boot. I put all the screws in and it was fine.

Just an idea thrown in the air....


Good luck!
 
Thanks for the reply, i am very puzzled now as my computer now works with the case on. I will see how it goes, i have done a virus scan and i am virus free
 
It does sound construction related. maybe next time you open the case and put it back on it won't work...
You are not forcing anything are you ? ?
 
No nothing, it all fits fine, nothing is being blocked and the screws are tightened but not too tight.
 
No loss of power so far but i think i have found out the problem, my MB has a 24 pin power supply connector but my PSU is 20 pin, it fitted if i did not use 4 of the pins but did not clip in. I think it could be getting loose. Would this be a logical reason. I think i will buy one of these
http://www.maplin.co.uk/module.aspx?ModuleNo=46201&doy=30m9
 
no, please dont....

unless you are using a dual core cpu, then a 20 pin psu is adequate for a 24pin motherboard. The normal p4 yellow/black 4 pin connector is "integrated" when using a 24 pin psu.

so, a 24pin connector=a 20pin connector+the yellow/black 4 pin connector. Clear so far?

the yellow/black (hereafter referred to as atx12v) connector should be a seperate 12v rail from the 20 pin connector. So that the cpu gets it's own clean stable 12v to regulate. If you use a 20pin-->24pin convertor, you end up splitting the 12v from the psu that runs the drives+mobo and using that to run the cpu and some parts of the motherboard from. Which can probably overstress the 12v rail.

From intel's own docs, use a 24pin psu if you have one, if not, then use a 20pin psu and connect the atx12v 4 pin connector too to compensate. Some 955 board even have a standard molex connector on the motherboard to compensate for 12v power (intel 955xbk springs to mind)

Short story, using a 20pin to 24pin adapter *may* cause a psu overload, which could damage the mb/psu/cpu depending on your particular psu limits.
 
Which motherboard are you using? DFI's sometimes have a problem when not used with a 24pin PSU. This isn't to say don't do what Werner has suggested.
 
Added firewire card today and guess what, it wouldnt boot at all but the fans were spinning. I looked on t'internet on another computer and found someone with a similar problem and the graphics card was faulty. So i removed my graphics card and the computer started booting properly (i could tell because the keyboard lights flashed). I then re-fitted the graphics card and it works still. I will see if i have any more problems and if i do i will exchange the graphics card
 

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