One FrontX part is the "Dual USB Type A Internal"
http://www.frontx.com/cpx108_2.html
The pinout is:
VCC X X VCC
D- X X D-
D+ X X D+
GND X X GND
X S-GND
When that mates to the Asus header, the Asus "NC" no-connector
is connected to the S-GND shield ground. That means the plastic
FrontX assembly has no DC path to ground, and the shield metal
on the FrontX metal shield is floating. It is waiting to be
zapped by static electricity, killing the Southbridge. At
least, that is what I'm assuming has happened here.
I'm surprised that the reset button worked, after the
computer froze. And that the Southbridge was usable for a few
moments, to allow the flash BIOS chip to be read via LPC.
Have a look at the Southbridge and see if there is any
sign of heat damage. Latchup does not have to produce a visible
result, to destroy a part, but other posters have been observing
the "meltdown" flavor of latchup.
Once you get the motherboard repaired under warranty (RMA), if
you want to connect the FrontX connector again, connect
the S-GND to a ground somewhere. Since you plan on using the
two 2x5 USB headers, that means there aren't any spare ground
pins around. Perhaps you can get a crimpable lug from the hardware
store, some wire, and fasten the lug to a PCI faceplate screw.
The other end of the wire has to go to the S-GND on each
FrontX assembly. If you buy 1/4 watt or 1/8 watt resistors at
Radio Shack, the ends of one of them might fit into the opening
on the FrontX wire. (The FrontX wire will have to be released
from its housing to do this.) Or, you could just cut the end off
the FrontX assembly and splice the end of the wire to your
home made ground connection.
The third prong on a North American ATX power supply, provides a
safety ground to the computer. For it to function properly, your
wall outlet should have a matching safety ground. Safety ground
should be connected to the chassis of the power supply, and when
the power supply makes contact with the computer case, the metal
chassis of the computer should be grounded too. Running a wire
to the chassis, as a means of finding a safety ground, will work
as long as you verify that there is ground continuity back to the
ground on the wall socket. If won't help to set up a gimmick ground
like this, if the chassis or PSU metal are in fact floating. At
least one European poster to this group got a shock from his
computer, and safety ground was the missing item.
Really, once you have suffered a "latchup meltdown", you should be
shopping for a cheap USB2 PCI card, and making the connections
to that instead. You could still destroy the PCI card with static
electricity, but it will be easier to replace that card, than
to RMA the motherboard again. One would hope the PCI USB2 card
is a bit more robust than the Intel Southbridge.
There are a lot of ALI chipset USB cards on Newegg, and this
one is pretty cheap - cheap enough to chuck if it doesn't work
well -
http://www.newegg.com/app/viewproductdesc.asp?description=15-201-206&DEPA=0
If Asus is reading this, it is time to change that "NC" pin
into a "GND" on the 2x5 USB header. Or, another option, would be
to solder some single GND stake pins to the motherboard, for
grounding things. The single stake pins could be kept close to
the header, but far enough away that a 2x5 assembly will not
bump into them. Some spare grounds are occasionally needed for
front panel audio, so some GND stake pins near FP_AUDIO would
help too.
Paul
