Computer Shuts Down

[Clayton]

I am having problems with a computer, this morning I turned on the computer
and once at the login screen as I am logging on the computer switches off, I
have restarted again and it is fine, PSU problem?

 

[PD43]

I am having problems with a computer, this morning I turned on the computer
and once at the login screen as I am logging on the computer switches off, I
have restarted again and it is fine, PSU problem?

Wait to see if the problem continues.

One instance isn't worth worrying about.

 

[Clayton]

sorry, I should have mentioned, it has happenned 3 other times over the last
6 months

 

[R. McCarty]

Use your BIOS setup category called hardware monitoring to
display the voltage rails of your PC. Most times you can see
problems ( or pending ) if the values are close the +/- tolerances.

Whenever you turn on a device it experiences a "InRush Current"
which is a momentary spike. If your supply is marginal that spike
may have caused the PS to abruptly shut down. Usually a rated
voltage can have a +/-5% range in a PC.

 

[Clayton]

It's a friends computer he had dropped off to me so it is happenning at his
place and mine, just wondering if I should swap out the PSU or motherboard?

 

[R. McCarty]

Supplies are fairly inexpensive. What Wattage rating supply is in
the PC currently. Also how many physical drives, Optical Drives
and does it have any type of High End Video card ( 512+ Megs
of Video RAM ). Gaming Video cards exhibit a very high load
on a PC's supply.

Power Supply quality is all over the map, so if you decide to get
a new supply don't buy the cheapest unit on the shelf and be sure
it's compatible with your specific motherboard. Not many things
worse than a return trip to the store to get a swap for the correct
part.

 

[Clayton]

It is a 350W PSU in the machine and yes the video card is using a 4 pin
molex plug from the PSU, 1 optical, floppy and hard drive
The motherboard is a ASUS P5VDC-MX

Now I have started the computer again and the screen has gone blank

 

[Clayton]

Good news, I plugged the PSU into a PC/SPS Tester and found the +3.3V -12V
+5VSB +12V -5V +5V lights came on except the PG light, so I guess the PSU
unit is gone

 

[R. McCarty]

Asus motherboards are very good quality, especially capacitors
which can be a problem on low-end MBs. I would suspect the
PS is at fault or at least the 1st diagnostic replacement to try. A
good quality 500-Watt supply will run ~$65. More if you get a
top tier brand like Antec.

 

[Bill in Co.]

You have that in your BIOS?

Use your BIOS setup category called hardware monitoring to
display the voltage rails of your PC. Most times you can see
problems ( or pending ) if the values are close the +/- tolerances.

Whenever you turn on a device it experiences a "InRush Current"
which is a momentary spike. If your supply is marginal that spike
may have caused the PS to abruptly shut down. Usually a rated
voltage can have a +/-5% range in a PC.

 

[Bill in Co.]

You actually have that option in your BIOS?

Use your BIOS setup category called hardware monitoring to
display the voltage rails of your PC. Most times you can see
problems ( or pending ) if the values are close the +/- tolerances.

Whenever you turn on a device it experiences a "InRush Current"
which is a momentary spike. If your supply is marginal that spike
may have caused the PS to abruptly shut down. Usually a rated
voltage can have a +/-5% range in a PC.