USB port not working

[KenV]

On my P4P800E Deluxe, the first USB port--the one closest to the side panel
and closest to the top--doesn't seem to work at all. It doesn't matter which
device I plug into it. The other three inboard ports work fine. I have 2
extra sets of 2 ports each connected to USB 5-6 and USB 7-8 on the MB, and
they all seem to work.

Is there a way to troubleshoot this and/or fix it without sending the MB
back (which would not be worth it for a single USB port)?

Thanks.

Ken

 

[KenV]

Since my original post has been "orphaned" so far, I'm going to add some new
info.

I called ASUS tech support, and they said that usually when only one USB
port isn't working, it's a short or grounding problem. They advised me to
take the MB out and run it outside of the case, and if the USB port worked,
it was a short fo the MB to the case. I did that, the port worked with the
MB outside of the case, so I insulated the case under the MB completely with
electrical tape and put the MB back in, but didn't screw it in. The USB port
still worked. The only card I had in was the AGP video card.

I then screwed the MB in, added all the cards, and the single port doesn't
work again! This sounds to me like an intrinsic MB problem--maybe a bad
connection when the MB is stressed or bent slightly, rather than a
short--there doesn't seem to be anything exposed on the case to short to.

What actually happens with the port is this. I put a working thumb drive in,
and it isn't recognized at all, but the USB port sees it because the device
manager refreshes immediately. Then, if I put my working HP scanjet into
that USB port, the device manager sees it as an unknown USB device, but it
won't tke the regular HP drivers for it. If I put the scanjet into the
working USB port next to the defective one, the scanner is recognized
immediately.

I'll call ASUS again Monday, and I suppose they will say to send the MB back
(it's a month old) , but the turnaround is 2 weeks or longer, as I recall.
And it's a major pain all around. Should I just live with this--missing one
out of eight USB ports--or is whatever is causing it going to eventually fry
the MB?

Any ideas or suggestions would be much appreciated.

Ken

 

[Malcolm]

Since my original post has been "orphaned" so far, I'm going to add some
new info.

I called ASUS tech support, and they said that usually when only one USB
port isn't working, it's a short or grounding problem. They advised me to
take the MB out and run it outside of the case, and if the USB port
worked, it was a short fo the MB to the case. I did that, the port worked
with the MB outside of the case, so I insulated the case under the MB
completely with electrical tape and put the MB back in, but didn't screw
it in. The USB port still worked. The only card I had in was the AGP video
card.

I then screwed the MB in, added all the cards, and the single port doesn't
work again! This sounds to me like an intrinsic MB problem--maybe a bad
connection when the MB is stressed or bent slightly, rather than a
short--there doesn't seem to be anything exposed on the case to short to.

What actually happens with the port is this. I put a working thumb drive
in, and it isn't recognized at all, but the USB port sees it because the
device manager refreshes immediately. Then, if I put my working HP scanjet
into that USB port, the device manager sees it as an unknown USB device,
but it won't tke the regular HP drivers for it. If I put the scanjet into
the working USB port next to the defective one, the scanner is recognized
immediately.

I'll call ASUS again Monday, and I suppose they will say to send the MB
back (it's a month old) , but the turnaround is 2 weeks or longer, as I
recall. And it's a major pain all around. Should I just live with
this--missing one out of eight USB ports--or is whatever is causing it
going to eventually fry the MB?

Any ideas or suggestions would be much appreciated.

Ken

Hi
Are the mountings brass posts or the clips type? Did your mounting kit come
with small fibre washers? If so place on the mounts before placing the MB
in. Are you using screws that are exceeding the mounting pad and touching a
component? Use small head screws if possible.

 

[KenV]

Hi
Are the mountings brass posts or the clips type? Did your mounting kit
come
with small fibre washers? If so place on the mounts before placing the MB
in. Are you using screws that are exceeding the mounting pad and touching
a
component? Use small head screws if possible.

Malcolm,

Thanks very much.

The mountings are brass posts. The are small paper washers that go onto the
screws to keep the screws from touching the MB on top of the MB. The screws
are very small, and I don't think they touch any components, but I'll have
to check.

Dumb question, maybe, but how do you place washers on the mounts and hold
them there, under the MB, while you're trying to put the MB in place and
screwing in the screws? And are there non-cuducting mounts of some kind?

Actually, the port worked when the MB was just sitting on all the mounts,
just not after I screwed it in. That's sort of why I thought it might be a
problem with the MB flexing.

Ken

 

[PB]

Malcolm,

Thanks very much.

The mountings are brass posts. The are small paper washers that go onto the
screws to keep the screws from touching the MB on top of the MB. The screws
are very small, and I don't think they touch any components, but I'll have
to check.

Dumb question, maybe, but how do you place washers on the mounts and hold
them there, under the MB, while you're trying to put the MB in place and
screwing in the screws? And are there non-cuducting mounts of some kind?

Actually, the port worked when the MB was just sitting on all the mounts,
just not after I screwed it in. That's sort of why I thought it might be a
problem with the MB flexing.

Ken

I think you are onto the real problem with that being a poor solder
connection that fails under the stress of proper fastener torque-down or
perhaps a PCB trace is faulty.

p00lb0y

 

[Malcolm]

Malcolm,

Thanks very much.

The mountings are brass posts. The are small paper washers that go onto
the screws to keep the screws from touching the MB on top of the MB. The
screws are very small, and I don't think they touch any components, but
I'll have to check.

Dumb question, maybe, but how do you place washers on the mounts and hold
them there, under the MB, while you're trying to put the MB in place and
screwing in the screws? And are there non-cuducting mounts of some kind?

Actually, the port worked when the MB was just sitting on all the mounts,
just not after I screwed it in. That's sort of why I thought it might be a
problem with the MB flexing.

Ken

Hi Ken
I use a small bit of glue... It is a pain... :-( I only fit the washers on
the bottom and also check prior to assembly just to make sure there is no
component on the underside that may interfere. Then can see the topside
when screws are fitted.

I would also put in one screw at a time as indicated in other posts and your
suspicions as it may be a flexing issue. Then you can see which is the
offending area.

 

[KenV]

I think you are onto the real problem with that being a poor solder connection
that fails under the stress of proper fastener torque-down or perhaps a PCB
trace is faulty.

I use a small bit of glue... It is a pain... :-( I only fit the washers on
the bottom and also check prior to assembly just to make sure there is no
component on the underside that may interfere. Then can see the topside
when screws are fitted.

I would also put in one screw at a time as indicated in other posts and your
suspicions as it may be a flexing issue. Then you can see which is the
offending area.

Malcolm and PB,

Thanks for your responses.

I called ASUS again this morning. They said that until I have isolated the board
from the standoffs, using electrical tape over each standoff and punching a
small hole in the tape for the screw, and then still have this issue with the
USB port, they would not swap out the MB. They said they see this all the
time--that the board ends up being grounded and causes this kind of problem.

So, I am going to take it all apart again and do it. In a way, I hope they are
right. But why do they build the boards with a conducting metal around each
screw hole?

Ken

 

[Dave]

Motherboards are SUPPOSED to be grounded to the motherboard plate.
Never permanently insulate between the board and the standoffs. This will
lead to worse problems than your original complaint.
The 'conducting metal' around the install holes is supposed to be there!
Problems arise when you use standoffs and or screws that touch beyond their
circumference.
I would take a look at the case and power supply first. Try installing the
board in a different case.

D.M.

 

[KenV]

Those are grounding holes which help reduce electrical noise, etc.

That advice is downright ridiculous. Save yourself lots of time
and simply remove the motherboard from your case, put it on
an antistatic mat and plug in a power supply. If the USB ports
start working you know it's a grounding problem.

Rick and Kevin,

Thanks.

Actually I did run it out of the case--I think I put it in an earlier post
somewhere. And the USB ports /did/ work correctly when the MB was outside of the
case. I had thought the MB was touching the case somewhere--not at the grounding
holes where it is supposed to touch it--so I put electrical tape in the case
where it could be touching, but not around the grounding holes, per se. In any
case, that didn't help.

So--ASUS is still convinced that it /is/ a grounding problem.

But if the grounding holes are normally meant to ground the MB in order to
reduce electrical noise (makes sense), why do they want me to completely
insulate the grounding holes? In other words, if it is supposed to be grounded
to the case, but the grounding is what is causing the USB port problem, it seems
to me as though there is no good solution.

What am I missing here?


Ken

 

[KenV]

Motherboards are SUPPOSED to be grounded to the motherboard plate.
Never permanently insulate between the board and the standoffs. This will lead
to worse problems than your original complaint.
The 'conducting metal' around the install holes is supposed to be there!
Problems arise when you use standoffs and or screws that touch beyond their
circumference.
I would take a look at the case and power supply first. Try installing the
board in a different case.

Dave, thanks. I just posted about the same thing in response to Kevin and
Rick--it just doesn't make sense to eliminate the ground.

I have a new, 500W Antec power supply and all the readings seem normal, no cold
booting problems, etc. And when connected to the same PS outside of the case the
USB ports do work normally.

I was thinking of getting a new case but wondered if that would solve the
problem since the MB now touches only the standard-size standoffs--nothing else
in the case that I can see.

I, too, wondered whether isolating the MB could cause other issues. As it is
now, if I just leave it as is and forget the one USB port that isn't working (I
have 7 others) am I risking damage to the MB over time?

Ken

 

[Malcolm]

Rick and Kevin,

Thanks.

Actually I did run it out of the case--I think I put it in an earlier post
somewhere. And the USB ports /did/ work correctly when the MB was outside
of the case. I had thought the MB was touching the case somewhere--not at
the grounding holes where it is supposed to touch it--so I put electrical
tape in the case where it could be touching, but not around the grounding
holes, per se. In any case, that didn't help.

So--ASUS is still convinced that it /is/ a grounding problem.

But if the grounding holes are normally meant to ground the MB in order to
reduce electrical noise (makes sense), why do they want me to completely
insulate the grounding holes? In other words, if it is supposed to be
grounded to the case, but the grounding is what is causing the USB port
problem, it seems to me as though there is no good solution.

What am I missing here?


Ken

Hi Ken
The holes are plated thru so even though it's insulated on the bottom,
fitting the screw will complete the electrical connection and ensure the
ground planes are bonded to the chassis.

 

[KenV]

The holes are plated thru so even though it's insulated on the bottom,
fitting the screw will complete the electrical connection and ensure the
ground planes are bonded to the chassis.

The difference is between intentional, proper grounds and
unintentional, improper grounds (or shorts). Asus is saying
you have at least one of the latter type, e.g. an extra, unused
motherboard standoff in the case that is causing a short or
improper ground on the underside of the board.

That does make very good sense to me.

The information I was missing was that the holes are plated through so that I
won't be losing the ground that it should have.

Looks as though I have some work to do, taking the MB out again.

Thanks very much.

Ken

 

[Paul D. Motzenbecker, Jr.]

Malcolm et al:
Greetings and hallucinations from just north of Fantasy Land
(Washington, DC)!
The standoffs (small brass posts) are electrically part of the
grounding. While small washers may help with cases that have bad hole
spacing, that is pretty much a thing of the past. Even with cheaper
cases. You will find that the trace around the mounting holes is always
ground and it helps to cut down voltage drop on long, thin traces to
have the ground connection in many places on the motherboard. I suspect
that there is a fault in the traces or something shorting.
Peace,
Paul
<snipped>