Power Problem

albanga

I just have a quick problem referring to PC power. I have a friend whos PC seems to run fine under normal operation, but as soon as he runs a Processor intensive application (WorldOfWarcraft) his system loses power and switches off.

I have not been able to have a look at it myself yet, but I just find this strange. I suggested it could be the power supply, and he went out and brought one, which has since been installed but the same problem persists.

Is there something i should be looking for in particular when i go over there to check it out. I have a multimeter to check the power connectors, but im just not sure what it could be. Im leaning towards fan or motherboard but im just not to good when it comes to power.

Thanks

keatron

Check the heat. Processor could be possibly overheating.

JDMurray

Does this problem happen both after the computer has just been turned on and also after it has been on for a long time? What is the make/model if the video graphics card, and does the card have its own connection to the main power supply?

If the problem happens when the computer is hot or cold, and there are no other power problems experienced when the machine is under a high hardware load (e.g., burning a CD), then I'd suspect the video graphics card itself. Do you have another card that you can swap out and see of the problem persists?

Plantwiz

Check the PS ratings. Confirm the PS is better then the minimum recommended for the Mobo AND Graphics card.

It is possible it's to lightweight of a PS to handle any work.

Wattage is important, (something better then 350W), but not as important as +12v AMPs. You want above 16A.

Assuming we are discussing a P4 or LGA class system. AMD can take a little less.

If P-LGA
It really needs a chassis with TAC1.1 compliance
PS rated for the MOBO and GC (GC usually needs a better PS then the Mobo).
Amperage is important 16-18A is ok, but 18+ is generally better.

FWIW

JDMurray

Plantwiz wrote:

Check the PS ratings. Confirm the PS is better then the minimum recommended for the Mobo AND Graphics card.

It is possible it's to lightweight of a PS to handle any work.

If it's an older computer with a newer graphics card then it's probably an underpowered PSU. I was guessing it was a newer system, but there's nothing in the description of the problem to indicate it is.

Good thinking, Plantwiz!

TheShadow

Reading the original message, the power supply has been replaced. Keatron's suggestion of overheat is most likely as video card overheat generally causes reboots and not power downs. So the question is what CPU brand is it. Intel systems lower the clock on over heat until the system cools off so on those systems you would see performance loss. AMD systems kill power on an overheat. The option can be disabled in the BIOS, however, I don't recommend it. The cut off value can also be made agressively high, that is safe to try for problem isolation. Most AMD models have a safe top end of 70 degrees C in the design manuals.

Plantwiz

While it states it has been replaced, we still do not really know replaced with what and are left to guess that it is a properly sized unit.

It would be nice if the original poster could reply and offer some more information. As it is, he/she has a few us here ready to assist him

JDMurray

Plantwiz wrote:

While it states it has been replaced, we still do not really know replaced with what and are left to guess that it is a properly sized unit.

Yes, exactly. Replacing a 350W PSU with another 350W PSU is not going to get that monster ATI (or whatever) graphics card running. Many people don't realize that there a finite capacity to how much power a PSU can output, and they can easily exceed that limit by upgrading their video card. I see people maxing-out their USB power capacity all the time by adding "just one more device."

TheShadow

What you both say is true. If there have been some major hardware changes then all bets are off. Generally though most cheap power supplies go into overcurrent suspend and don't actually power off. The system should crash and the supply would come back up causing a reboot. A quick test here on a load block across the 5 volt line seems to indicate this to be true, but you never know. As I recall many BIOS allow different scenarios on power loss.

Plantwiz

Well, we could be looking at the line power too. Perhaps his friend has the System plugged into a wall and not a UPS (like an APCSmartUPS) and also has a TV, Laser Printer, microwave, etc... all on teh same line. Maybe the line it's plugged into is only a 15A and there is already too much draw.

I do agree, I have seen a reboot when the PS was overdrawn. I've also seen the system simply shutoff with a Heat issue.

Definately a few things to check:
PS
Mobo
BIOS
GC
PowerSouce
UPS or not


Just need the original person to pop back in