Mikkel L. Ellertson wrote:
Robert wrote:
I got to this party late but thought it might be worthwhile to mention
this.
I put a Canoscan LIDE 35 that has been collecting dust on an old P3
machine and it "just worked". I moved it in to this machine, where I
really wanted it, and it "JUST BECAME VERY INTERMITTENT". No external
hub, no root hub port seemed to make any difference -- until I bought an
externally-powered hub to drive the scanner. Shazam! It hasn't missed a
beat since.
Obviously, the bus-supplied power from this m/b,p/s combination was
marginal.
The m/b that worked 100% - ASUS P3V4X Rev 1.xx
Intermittent m/b - ASUS A7N8X Deluxe Ver 2
Both with commodity p/s mfg by Obscurename, Ltd.
Just a stray thought - check the A7N8X to see if there are jumpers
to select where the USB ports get their power. There may be a choice
between +5 and +5VSB - if jumpered for +5VSB there may not be enough
power for the everything connected to the USB bus. (There may be
more then one jumper, for different USB connectors.) Just be aware
that changing the jumper to +5 will disable the ability of USB
devices plugged into that port from waking the system from suspend.
Mikkel
Good catch; thanks! Yes, the option is available and there are multiple
jumpers, as you suggested. I haven't looked at the jumpers yet but based
on this excerpt from the manual, indicating that the default is +5V, I
doubt that it/they has/have been changed because I had zero USB devices
when I bought this m/b. Manual sez:
3) USB Device Wake-up (2x3 pin USBPWR12, 34, 56)
Set these jumpers to +5V to allow wake up from the S1 sleep state (CPU
stopped; RAM refreshed; system running in low power mode) using the
connected USB devices. Set to +5VSB to allow wake up from S3 sleep state
(no power to CPU; RAM in slow refresh; power supply in reduced power
mode). The default setting for the three jumpers is 1-2 to select +5V
(because not all computers have the appropriate power supply).
