URGENT computer turns on and off repeatedly, needed for school

[T1LuX]

Really need everyone's help with this

hey guys I needed to check if my mobo had suffered static damage after hearing a click type sound when handling it so I borrowed my dads psu to see if I could get any signs of life from it, thankfully the led lit up.

however, when I plugged everything from my dads pc bak in and tried turning it on, it turned on for about half a second, then turned off for about 5 seconds then turned on for another half a second and just kept going through that cycle until I turned the power off.

I've tried rebooting with only cpu and ram, swapped ram, cleared out the heatsink and reapplied thermal paste, check all connections, but the same thing happens.

I really need your help fixing this guys, my little brother needs this computer for schoolwork, and since we are using distance ed, most of his schoolwork is done using this computer

if I can't fix it I'll probably end up having to buy a new motherboard for him, which could cost over $80, and I really don't hav the money, that and my dad is getting upset/annoyed at me about it.

system specs

CPU: core i5 750
RAM: 2x2gb 1333mhz Elixir ddr3
HDD: Seagate barracuda 7200.12 500gb
GPU: evga gts250
MOBO: gigabyte ga-h55m-d2h
PSU: hipro hp-p3507f5w 300w

system was running completely fine until I took it apart

 

[inanition02]

Did you plug in both the 24 pin primary and the 4/8 pin secondary power?

 

[nikorr]

I would try stronger PSU, min. 450+Watt

 

[nikorr]

Can u try to remove the GPU and use the mobo HDMI?

 

[tlmck]

For one thing that video card is too much for a 300 watt power supply. If the motherboard has integrated video, take out the GTS 250 and use the integrated. You don't need the GTS 250 for homework.

It should work assuming you did not damage the power supply.

 

[abekl]

That static sound you heard might have scrambled the cmos. Try clearing the cmos and see if that helps.

 

[inanition02]

I would try stronger PSU, min. 450+Watt

But if it worked before, I wouldn't think that would be the issue.

 

[T1LuX]

Did you plug in both the 24 pin primary and the 4/8 pin secondary power?

yes I plugged in both and made sure they were secure

I removed the gpu, wat do u mean by using the mobo HDMI? the screen doesn't thave time to turn on

 

[T1LuX]

yeh that's right Inanition02, although I've already tried it without the gpu,

abekl, that static sound was from my Asus mobo, not my dads gigabyte one

 

[nikorr]

But if it worked before, I wouldn't think that would be the issue.

If u overload the PSU will work, but not for good. It will degrade quickly and one day it will not start anymore.

If u will buy 850W PSU and all u need is 750W, and u will play daily, than 1 year later it will not have capacity to power it up. Everything degrades.

If u will check some reviews than u will see that Antec EarthWatts 430 have actually 560Watts of power, so it last longer than others.

If u will not abuse the power any of them will last at least 3 years.

 

[nikorr]

yes I plugged in both and made sure they were secure

I removed the gpu, wat do u mean by using the mobo HDMI? the screen doesn't thave time to turn on

It may not have time because the power is not enough with GPU card in, so if u remove it, u save some Watts and it may boot, right?

 

[inanition02]

If u overload the PSU will work, but not for good. It will degrade quickly and one day it will not start anymore.

If u will buy 850W PSU and all u need is 750W, and u will play daily, than 1 year later it will not have capacity to power it up. Everything degrades.

If u will check some reviews than u will see that Antec EarthWatts 430 have actually 560Watts of power, so it last longer than others.

If u will not abuse the power any of them will last at least 3 years.

Things do degrade - but not quite that fast. And if it worked yesterday and then he took it apart and put it back together and now it doesn't work, I'm more inclined to think it was because of the taking it apart/putting it back together rather than the natural degradation.

 

[T1LuX]

I can try my grandad's psu later tomorrow then, I'm not sure of its wattage though.

 

[nikorr]

Things do degrade - but not quite that fast. And if it worked yesterday and then he took it apart and put it back together and now it doesn't work, I'm more inclined to think it was because of the taking it apart/putting it back together rather than the natural degradation.

U know, it is just a process of elimination what it could be....

So first thing I see is weak PSU for the system.

 

[nikorr]

Try,


Reset the BIOS?
How To Clear CMOS @ http://pcsupport.about.com/od/fixtheproblem/tp/clearcmos.htm

 

[T1LuX]

my dad mentioned that I'd done this before awhile time ago (I can't remember) and that he and my grandad were able to fix it, and i can't remember them replacing any parts

 

[T1LuX]

Try,


Reset the BIOS?
How To Clear CMOS @ http://pcsupport.about.com/od/fixtheproblem/tp/clearcmos.htm

thanks I will try that as soon as I can

 

[T1LuX]

clearing cmos fixed that problem, however, now, it stays on but the monitor doesn't receive any signal, case power led blinks on and off then stays on, and hdd led blinks like normal then stays on aswell, any suggestions?

 

[T1LuX]

FIXED

turns out I'd just forgotten to connect the pcie power for the gpu, simple mistake but I guess everyone does it every now and then

thanks heaps for your help guys, especially nikorr

 

[nikorr]

Well, it works and no damage was done : ) Good luck T1LuX!