Help PC not coming on

[sempi]

hi guy's can anyone help me out here
bought a new cooling fan for pc today and took out old one but then found new one did not fit, so put everything back together and now it wont start. when powered up cooling fan and power supply fan both come on for about 3 seconds and then machine switches off and i need to remove mains supply before it will power up (or try to) again but just does the same again.
i have tried taking out memory and power supply to motherboard and making sure they are in ok but still nothing, it must be something i have done as it was working ok before i went out to buy cooling fan
any help greatly appreciated

 

[wiggy9906]

If it's a brand PC such as Dell/HP they sometimes have case sensors and won't power up without the case being seated properly.

Also check the processor is seated properly. If the motherboard has a fan speed sensor ensure the fan is correctly connected. It also might be worth resetting the bios, you should have a couple of pins (sometimes a button) marked BIOS or CMOS short these pins (or press button) this will reset the BIOS to factory default.

Good Luck

Wiggy

 

[sempi]

have just tried another power supply and still the same, cooling fan and power supply fan come on for about 3 seconds max. before power just cuts off
i have also taken out the heat sink and fan and put back in again making sure they are secure but still no difference

 

[Sameira]

try disconnecting all extra bits, take off ur drives floppy etc any extra cards jus leave the graphic card in, ur mouse an keyboard.

Did u take the processor out? if so take it out again and put it bak in make sure its in properly and see if u hav bent any pins.

Also try without any memory chips in. If not remove tht battery on ur motherboard for about 5 secconds or wotever (reset teh bios) u probably hav to do sumamt wit a jumper aswell (chk ur manual)

try a different power cable


thts all i can think of 4 now, i hope ur board an pprocessor are not f*cked

 

[sempi]

try disconnecting all extra bits, take off ur drives floppy etc any extra cards jus leave the graphic card in, ur mouse an keyboard.

Did u take the processor out? if so take it out again and put it bak in make sure its in properly and see if u hav bent any pins.

Also try without any memory chips in. If not remove tht battery on ur motherboard for about 5 secconds or wotever (reset teh bios) u probably hav to do sumamt wit a jumper aswell (chk ur manual)

try a different power cable


thts all i can think of 4 now, i hope ur board an pprocessor are not f*cked

thanks mate
i have psu connected to mboard only, all cards removed except graphics
have checked processor and it seems ok (clean and no bent pins) and have removed and replaced battery and also tried another power lead and with memory out i get a beep right before power goes off

tried the above steps one by one and powered up each time but still the same result in fact i would say it is only about 2 seconds before power goes off

 

[sempi]

now for the latest
i have put in the processor from my sons pc and the power stays on, so i have reconnected everything but keep getting the "no input signal" on monitor any ideas!!

 

[sempi]

i have just tried another graphics card in pc and still no signal so i am guessing it is from my origional problem with the pc not starting, power is staying on but i do knot know if pc is booting up properly as i cannot see anything, i have tried monitor with another pc and it is fine

 

[paul01]

it sounds like your processor is damaged.. did you remove the processor when you changed the fan?

also do you know what type of processor you have .. Athlon /Duron Sempron etc.

a lot of processor fans can cause damage to the board when you put then on if your not careful.. pushing the clips down to far can damage the motherboard or the side of the processor .. can you see any marks around the edge of the processor..?

 

[sempi]

it sounds like your processor is damaged.. did you remove the processor when you changed the fan?

also do you know what type of processor you have .. Athlon /Duron Sempron etc.

a lot of processor fans can cause damage to the board when you put then on if your not careful.. pushing the clips down to far can damage the motherboard or the side of the processor .. can you see any marks around the edge of the processor..?

i did remove the processor and then put it back cannot see any marks
the fan was miles big so i did not even try to fit it
put back old fan and pc would not power up (pcu and cooling fan were on for about 2-3 seconds before shutting down)
my processor was an Athalon xp tried processor from sons pc and the power stays on but no signal to monitor (his is also an Athalon but not sure of exact type) so i do not know if pc is actually booting up or not
i have tried my origional processor back in but same as origional problem again it cuts off after 2-3 seconds

 

[sempi]

have just tried booting up again and noticed that i am not getting any power to my keyboard (usb) although my usb mouse lights up
this is getting more confusing by the minute...lol...
tried keyboard in laptop and it is ok

 

[troopy]

I have an athlon XP and if the heatsink is not seated perfectly on the processor die I get the same problem you are having, Have you used a thin smear of heat transfer compound and making sure both the die and the heatsink face are perfectly clean?

Also, as someone mentioned earlier, the die's are incredibly eaasy to chip/damage when mounting the heatsink/fan assembly.

 

[sempi]

I have an athlon XP and if the heatsink is not seated perfectly on the processor die I get the same problem you are having, Have you used a thin smear of heat transfer compound and making sure both the die and the heatsink face are perfectly clean?

Also, as someone mentioned earlier, the die's are incredibly eaasy to chip/damage when mounting the heatsink/fan assembly.

have tried all that m8, i think my own processor is kaput, i must have done something to it when i took it out but it looks ok and with the other processor in power is staying on ok but don't think pc is booting up or at least the monitor and keyboerd are not getting a signal

 

[Explosivo]

i think if you had a faulty cpu you would still get the bios on screen and it would say failed cpu test or somthing.

sounds like a fault on your board to me.


i could be wrong though

 

[Explosivo]

it could also be your psu

 

[Dutcho]

Try re seating the cpu and fan, I have knwn this problem to happen when the fan is not seated correcly and pushs on the cpu

 

[sempi]

have just put sons psu in and still the same cooling fan is on but no signal to monitor and nothing to my usb keyboard
have tried my own cpu back in and power shuts down after about 3 secs, i guess it is heading more towards a problem with the motherboard now?
i should have left well alone and not bothered about a noisy fan, spent a tenner on it and looks like i have f****d up pc !!!

 

[sempi]

just tried it with no cpu in to see if i got a signal to monitor, nothing still the same no beeps or anything

 

[sempi]

given it another go with no memory in this time and no beeps with and without cpu in so i guess i have a prob with my motherboard now

 

[sempi]

anyone know of any good sites for motherboard/processor combinations
something not too expensive ..lol..

with all the probs i have just had thought i would give you another laugh, to reset cmos on my mb you have to put a jumper on not remove one, so i took one from my sons as i have taken everything else to try and get mine working but it was a while ago and like the stupid fecker i am and to top off the day i am having
yes you guessed it
i can't remember where the fecker goes ..lol... so now his will probably not work when i put it back together and it can just follow mine out the window as i cannot take any more

 

[larssonn]

given it another go with no memory in this time and no beeps with and without cpu in so i guess i have a prob with my motherboard now

If you have an AsRock mobo of the 754 variety, it brings up a 'problem' similar to that. I do the web maintenance for a local PC shop and I remember the boss going on about that.

What spec is the CPU?