Archived from groups: alt.comp.periphs.mainboard.asus (More info?)
In article <firstname.lastname@example.org>, tecknotot <> wrote:
> Can anyone help me and answer this? My last motherboard, my mouse
> light was not always on when my PC was OFF and with this new one, I
> noticed that its always on.
In the past, there were three or four headers on the motherboard,
that allowed the user to choose to power PS/2 mouse/keyboard or
USB devices, from either +5V or from +5VSB.
It looks like this is the first Asus motherboard to do away with
those headers. The user manual doesn't have any pictures of the
layout, so I cannot check and see if there is room on the
motherboard for the three pin header or not. (The designer could
have placed the header pads/holes on the board, and then
manufacturing removed the pins.)
Based on your observation, it seems your ports are being powered
by +5VSB. This is fine, as long as the ATX power supply has enough
current to run all the devices connected from +5VSB. This could
be a problem, for example, if the USB ports are powered by
+5VSB, and you use bus powered USB scanners or ADSL modems. In
a case like that, with enough 500mA USB device loads, you might
manage to overload the +5VSB output. And, without headers on the
board (they would be labelled USBPWxxx or the like) to choose
powering from +5V, you would need to use an external powered hub
to solve the powering issue.
(I hope Asus gets a clue, and puts the color pictures of the
motherboard back in the manual, as the picture helps in diagnosing
problems like this.)
As far as I know, Asus is not smart enough to make the powering
choice switchable in hardware. It could be done, but would cost
a few bucks. Removing the USBPWxxx headers from the
motherboard probably saved Asus a whole $0.10 per board.
A big win for their finances :-(