[solved] computer start up problems

[mcd840]

hi all, just built myself a new gaming computer, the other day it has started having problems, when i start it up it shuts down again then starts back up again and eventualy it sometimes starts and other times it doesnt, i have not changed anything since it was working fine to begin with, what i did notice when i opened the case is the CPU fan tries to start but fails to do so, but as i said sometimes it eventually does start.

ps all the parts are brand new and less than 4 months old.

 

spec as follows

 

COOLERMASTER HAF 912 CASE

ASUS P8Z77-V PRO MOTHERBOARD

INTEL CORE I5 3570K 3.4GHZ CPU

PSU CORSAIR TXM650W

MEMORY CRUCIAL 8GB DDR3 1333MHZ BALLISTIC SPORTS

GRAPHICS CARD ASUS NVIDIA GTX550TI TOP

OPERATING SYSTEM WINDOWS 7 64 BIT

 

any help appreciated, thanks !

[Plastic Nev]

Hi and welcome to Extreme Tech Support - Free PC Help.

That fan not running will be the cause of the near immediate shut down, as the CPU will heat up very quickly without it and automatically shut down.

 

First check the fan connections, unplug and push back on again to make sure.

If still a problem, then ideally a volt meter is needed to check that power is there when the fan is stopped.

 

That must be done with extreme care and if not sure, find someone qualified who can check, as it will point to either a faulty fan, or faulty power supply.

 

Nev.

[mcd840]

Hi nev thanks for the quick reply i also meant to say that it only has this problem when the computer has been off for a few hours or all night, but if you do get it running and switch it off it will start again no problem i will go and check the fan connections after this post

[Plastic Nev]

Hi again, a bit doubtful, but there could also be a motherboard fault not allowing power from the power supply to the fan, but my bet is the fan itself.

If so, providing you still have proof of purchase you should be able to get an exchange for it.

 

Nev.

[mcd840]

hi nev went and checked the fan connections all ok, but what i did notice when i tried to start it the now as i had the case on its side as the psu is in the bottom of the case was the psu switched on and off and was running then not running the same as the cpu fan could it actually be a faulty psu

[Plastic Nev]

Hi, before we say yes, check the physical start button on the front of the case and the wiring to it, if the button or switch behind is faulty that could first send the signal to start up, then send another which will make it shut down.

 

The way to check will be remove the connections to the button and momentarily short across the pins on the motherboard, a small coin or screwdriver will do.

Then remove it out of the way, if the power supply shuts down then, it could be the supply, or again the motherboard.

 

Being a self build, you just might have a small spare screw between the motherboard and case, or even a wrongly fitted motherboard support pillar which could just be shorting tracks on the motherboard, all things to check first before we say it is the PSU.

 

remove the motherboard from its mountings and lift it enough to be sure there is nothing touching any part of the case, slip some card or a sheet of stiff paper under to insulate it, then try again.

 

Nev.

[mcd840]

hi nev pulled the front and sides off the case and checked switch and wiring, all ok (should be as case only a couple of months old) and lifted the mother board up and checked underneath for anything and slid card beneath it and tried but still the same, you can also see the fan on the power supply starting and stopping and starting and after a few starts and stops it cames on but as i said before not from cold i think it only started this time as i had it started quite a few times to test it like before

[KenB]

Hi mcd840 (just butting in here Nev :) )

 

I suggest that you strip the hardware etc off the motherboard and leave only the 20(4) way connector from the PSU.

If the CPU fan and the PSU fan are still intermittent on start-up then I would suspect the PSU.

 

see here:

http://s13.zetaboards.com/kenspchelp/topic/6964867/1/#new

 

The simplest test is to swap it. It does not need to be the same Wattage.

[mcd840]

hi ken stripped everything off the computer and just left the 24 pin plug in and the cpu fan barely moved and the psu fan was the same but i then plugged the 8 pin power plug in as well and it tried to move the cpu fan a bit and also i got lots of beeps ps i am trying to think were i could get another power supply to try as well

[Plastic Nev]

Hi, back again, have to work during the week ha ha.

I think now though the PSU is the fault, as Ken suggested if possible to borrow one from a friend is a great idea, however yours being nearly new, it will be under warranty so you should be able to get it replaced OK.

Try and borrow a PSU first though, as that, if it works OK, will prove beyond doubt that your PSU is faulty.

 

Nev.

[KenB]

You could ask at a small pc repair shop if they have a second hand one that you could borrow to test with a view to buy.

They should have no problem with that.

[mcd840]

hi ken and nev thanks for all the help and will try and borrow a psu tonight or tomorrow and keep my fingers crossed that this will solve it,i just cant believe that something this new is broken already (bought in august) and it being quite a good make and dear one (to me) a corsair at £76 and as you say though at least it is under warranty,ps will get back to you after i get hold of another psu and let you know if that sorts it

[mcd840]

hi again just to let you know i got a psu from my neighbour and i plugged the 24 pin plug in and it started the case fans ok and the psu is running, but the cpu fan did not start, i take it i will have to get a psu with the 8 pin connector to power this as well as my motherboard has two connections and the psu i got from my neighbour has only the one 24 pin power connection

[KenB]

i will have to get a psu with the 8 pin connector to power this as well

Yes - the 8 pin connector powers the Central Processor and presumably the fan too.

 

This is why it didn't make any attempt to boot up - but kept case fans running.

[mcd840]

hi ken tried starting it this morning with the corsair power supply but it hardly moved anything and kept switching on and off as usual so i take it that it is the psu that is broken so will phone ebuyer up were i bought it today to see what they say

[KenB]

If the other one is spinning fans etc and the Corsair isn't it looks like it is due for a return to seller.

[mcd840]

hi ken and nev just an update, phoned ebuyer yesterday and told them the problems with the psu so they emailed me a free returns postage label and told me to parcel it up (lucky i still had all the boxes) and royal mail parcelforce collected from the house this morning and ebuyer will send a new one when they get that one back so great service from ebuyer and will let you all know how i get on with the new one when i get it, probably next week sometime

[KenB]

That is good service - let us know how you get on :)

[mcd840]

hi again ken and nev just an update to say i got the new psu and all now sorted and to say thanks again for your help

[KenB]

That is good to hear - glad everything worked out for you :)

[Plastic Nev]

Hi mcd840, glad to hear it is sorted, another team effort Ken. http://i7.photobucket.com/albums/y282/plasticpig/mw_handshake.gif

 

Nev.