Power loss in USB Devices when computer is under load

[Kompass]

Hi,

MoBo: Asus CUVX, P3 / 933 Mhz, 2 IDE drives, 2 DVD Writers, very modest video card. PSU changed last year Enermax 400 W.

I have a curious problem I wonder if it is a MoBo issue. Sometimes, it seems like there is not enough power in the USB 1.1 plug. Then some (or all USB devices) stop working. For example the light of the USB mouse shut off and the mouse is no longer responsive.

I have tried to install an expansion card with 4 USB 2.0 plugs (the good one using NEC chip). But I also experienced the same power loss issue. I got the external USB hard drive totally corrupted twice, I suspect that it was the consquence of the USB power loss when the computer is under load. The USB2 card has been now removed.

Now I use very few USB devices, just the wireless receiver for mouse/KB. And from time to time an USB key. Even though, when the DVD Writer (LG 463B) start working an intensive task, let says to copy 4 GB from the DVD to the hard drive, my USB mouse shuts off about 1 minute later. The only way to reactivate the mouse is to unplug and replug the USB plug. Strangely enough, there is no problem with the other DVD drive (LG H22).

Q1. What is the reason that provokes the power loss of the USB devices?

Q2. How come an additional USB PCI card is also affected by the same problem?

Q3. Is there any fix?

Thanks you very much in advance for your help.

 

[Binky]

Sounds like the old P3 motherboard is just about dead. I'd be pointing more at some obscure motherboard or CPU failure than something related to the power draw of being under load.