• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Computer Rebooting For no reason

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

jadams

Member
Joined
Mar 27, 2002
Location
Burnaby, BC, Canada
My computer has been rebooting all by itself lately. Nothing has been changed in a while, so I'm not sure what the problem is really. I think it could be the power supply, but it is a 400w Antec.

One weird thing, is that with my old mother board, all my voltages were bang on or a little high, on current board (asus a7n266-vm my +5v sits around 4.5, my +12v sits around 11.5, my -12v is always over 16(???), and +3.3v is usually 3.2 or 3.3.

The system is my main system in my sig.

Anyone have any ideas what could be causing the reboots?

Thanks,
Jeff.
 

nut581

Member
Joined
May 29, 2001
Location
Columbus, OH
i had same problems with my old 300W PSU supplying +/- 4.85V on +5V line. at 4.5V, better get a new PSU (probably yours is defective??).

I read somewhere on the forum that if under full load your +5V line supplies minimum 4.9V, than that's cool :) .. lower than that, expect random restarts and BSOD.

cheers :)
 

Rakk

Member
Joined
Oct 31, 2002
Location
UK
I had this problem on my P3 setup a while back. It turned out to be the motherboard chipset overheating - maybe check your temps all over?
 
OP
J

jadams

Member
Joined
Mar 27, 2002
Location
Burnaby, BC, Canada
temps right now: 25c inside case, 29c on MB, 31c CPU
Don't think thats the problem unfortunatly.

using a vantec Tornado on my CPU, and its so loud I would know if it wasn't spinning! hehe

Jeff.
 

rogerdugans

Linux challenged Senior, not that it stops me...
Joined
Dec 28, 2001
Location
Corner of No and Where
I'll say that there is a definite reason why your computer is rebooting: low 5v line.

It is very rare for an AND chip to be stable at anything less than 4.78v.

Voltages fluctuate depending ob a few factors: quality and capacity of psu, load on computer and load on psu (# of devices, etc.)

I use 4.84v as my minimum normal voltage when overclocking because load variation etc. will occasionally drop the reading to 4.8v or below.

I am surprised it runs at all with only 4.5 volts!

A couple of thoughts:
have you checked voltage at a molex?
Are you running any High Performance fans from mobo headers?

You may have a bad mobo or psu there.
 
OP
J

jadams

Member
Joined
Mar 27, 2002
Location
Burnaby, BC, Canada
1. I have not checked from a Molex
2. Just regular old fans ~30cfm on the mobo

I think it is the mobo because same PSU on my old board worked well. The voltages have always been kinda low since I put this board in.

Hoping to get a new NF2 or just a 400 mobo sometime soon, so I will probably just live with it till then. THEN if it continues I will get a new PSU.

Thanks for all the suggestions! Keep em comin'! I'll keep checkin'

Jeff.
 

germanjulian

Member
Joined
Apr 28, 2002
Location
Frankfurt/London
less then a year old!!! warranty!!!!!!!!!
get it replaced. shouldnt be a problem. 400W is plenty i dont see why ur 5V would be so low, disconnect 3 case fans as check ur voltage and see what happens.
oh and minus voltages displaying incorrectly happens a lot! no worries there.
my 5V is at 5V am i lucky or what!
 
OP
J

jadams

Member
Joined
Mar 27, 2002
Location
Burnaby, BC, Canada
hehe was waiting for someone to mention warranty. hehe well um you see, I kinda voided the warranty hehe.

I replaced the cover on it with a clear blue one, so no sending it back. I don't have a problem with buying a new one, would just mean other computer stuff, like a new mobo, are delayed.

No time to play with it right now, I'll tinker with it this weekend.

Jeff.


EDIT for horrible grammar.
 

Fess_ter

Registered
Joined
Apr 9, 2001
Location
Indiana
What OS are you using?
If its XP, it has a Blue Screen of Death error trap in the default setup that will reboot the system rather than show you the BSD.
It can be disabled which may help you better diagnose if its Power Supply or not.

Fess_ter
 

CizMeyeAzz

Registered
Joined
Jul 20, 2001
Location
Vancouver, Beautiful B.C. Canada
Yo Jadams,

Your problem is the power supply because your 5V is below the 5% tolerance that motherboards allow.

DONT CHANGE THAT ANTEC PSU
You said you have an Antec 400w power supply, I have the same PSU as you do. The beauty of this power supply is that it has pots to adjust the voltage. My 5v rail wuz running at 4.75v and since tweaking it, its at 5.05volts. My 12v rail was at 11.6v and now its at 12.03v. The link below will show you how to change your voltage with step by step instructions and pictures.

http://www.3dxtreme.org/psumod.shtml


Cheers,

CizMeyeAzz
 

Lord Moreira

Banned till 9/16/03
Joined
Jul 29, 2002
Location
U.S
My brand new Antec true430 power supply gives me 4.89v and up on the 5+ idle i have 3 hardrives, 1 cdrom 4 case fans and the tt smart 2 on the cpu , is that low also?
And would it have the pots inside to adjust?
Not going to void my warranty yet if it is defective i'll just return it.
i had 1 blue screen and reboot with it already but i did have my rig overclocked FSB 145 1800+ on a 266 @ 1.8v
it's good now that i'm running stock again.
just not worth it to overclock if it's a FSB OC , to much @ risk for me.