Very strange problem with front panel usb ports

[goodpsusearch]

Hello.

I have 3 identical PC Cases and 1 black that is different.
All the 4 cases have front panel USB ports.

I also have 2 different motherboards:
Intel Desktop Board D845PESV
Gigabyte GA-8IPE1000-G (rev. 3.x)

Every one of them supports USB 2.0 and has front panel USB headers.

Intel motherboard D845PESV works with USB 2.0 ports of every PC Case.

But Gigabyte GA-8IPE1000-G (rev. 3.x) works only with the black case ports...

If I connect it to any of the 3 other cases USB ports and then mount any usb device to it I get "unknown usb device" message...

I have double checked the connections and they are right. I have also tested the usb ports and their cables with my multimeter and they show negligible resistance.

One last thing to mention: The Gigabyte mobo has an external usb bracket that connects to the back side of the case like a PCI card. I swapped it with the front panel USB ports and it still worked while the front ports gave "unknown usb device".

So, what the fuck happens???

[PCBONEZ]

Re: Very strange problem with front panel usb ports

Is the Intel and Gigabyte USB pinout the same on those two boards?
You may have reversed data+ and data-. [or whatever that's called..]
.

[yyonline]

Re: Very strange problem with front panel usb ports

GA-8IPE1000-G is Intel 865 chipset. I've seen a lot of 865 chipsets with dead USB ports. It seems to be a weak point for this particular southbridge.

[PCBONEZ]

Re: Very strange problem with front panel usb ports

GA-8IPE1000-G is Intel 865 chipset. I've seen a lot of 865 chipsets with dead USB ports. It seems to be a weak point for this particular southbridge.

If that were the problem then it wouldn't work in the black case either.
.

[PCBONEZ]

Re: Very strange problem with front panel usb ports

Does black case and Gigabyte adapter have the three ground wire configuration and the other cases not?
[Shot in dark.]

[ratdude747]

Re: Very strange problem with front panel usb ports

what it might be is this:

some boards (MSI comes to mind, as does really old asus) had the pinouts for each port on the header reversed... so if you got the plug upside down it would still be correct.

example:

1 5v 2 NC
3 d+ 4 gnd
5 d- 6 d-
7 gnd 8 d+
9 NC 10 5v

also, I remember the old FIC boards (pIII and early p4), like the ones in compaqs of that era, used a screwball pinout... i fried a board hooking up a compaq usb port card to a standard pinout header. pico fuse went bye bye.

[kaboom]

Re: Very strange problem with front panel usb ports

It sounds like the signal pair(s) is(are) reversed. I had to eliminate a USB plug on a hub for 'playing around' purposes and got D+/D- reversed. Same thing- 'Unrecognized USB device."

I wouldn't be so quick to believe the -whole- header is reversed. That would put 5V on the ground and shield. The fuses would blow or the polyswitches would have to be 'reset' and the USB device would have no power, resulting in nothing when plugging something in.

Reverse the green and white wires. Use a pick or awl to release the tabs that hold the contact in the connector body.

-Paul

[goodpsusearch]

Re: Very strange problem with front panel usb ports

Is the Intel and Gigabyte USB pinout the same on those two boards?
You may have reversed data+ and data-. [or whatever that's called..]
.

They are the same!

Does black case and Gigabyte adapter have the three ground wire configuration and the other cases not?
[Shot in dark.]

What do you mean?

what it might be is this:

some boards (MSI comes to mind, as does really old asus) had the pinouts for each port on the header reversed... so if you got the plug upside down it would still be correct.

example:

1 5v 2 NC
3 d+ 4 gnd
5 d- 6 d-
7 gnd 8 d+
9 NC 10 5v

also, I remember the old FIC boards (pIII and early p4), like the ones in compaqs of that era, used a screwball pinout... i fried a board hooking up a compaq usb port card to a standard pinout header. pico fuse went bye bye.

Both the black case and the other 3 cases have the same pinout.

The 2 mobos have the same pinout too according to their manuals.

[goodpsusearch]

Re: Very strange problem with front panel usb ports

The motherboards pinout here...

[kaboom]

Re: Very strange problem with front panel usb ports

What's different between the cable to the 'backplate' and the one to the front ports? Can you see anything different about the shielding/twisting of the signal pair between the two?

Try and 'force' that Gigabyte board to do USB 1.1 or even 1.0.

If you plug a low bandwidth device, like a mouse or K/B, into the front panel ports, does the GB board still throw "unknown usb device?"

-Paul

Edit:
Any kinks or sharp bends in the cables that seem to be a problem?

[goodpsusearch]

Re: Very strange problem with front panel usb ports

OMG!

I connected a usb mouse and a usb keyboard and they were properly recognised and worked!

Then I connected a 500GB 2.5" hard drive, the most power hungry device I could find.......... IT WORKED

But the usb flash drives and an SD card reader are not recognised. Instead I get the "unknown usb device" message...

That doesn't make sense..

[ratdude747]

Re: Very strange problem with front panel usb ports

OMG!

I connected a usb mouse and a usb keyboard and they were properly recognised and worked!

Then I connected a 500GB 2.5" hard drive, the most power hungry device I could find.......... IT WORKED

But the usb flash drives and an SD card reader are not recognised. Instead I get the "unknown usb device" message...

That doesn't make sense..

sounds like an issue with the plugs on the card reader and flash drive and the ports themselves on the case in question... if the port is old, it may have become looser and as a result other old worn down plugs my have poor connections... some of my old usb cables have grooves where the spring parts of the usb port make contact...

[kaboom]

Re: Very strange problem with front panel usb ports

Bingo!

This is a bandwidth or termination issue.

The mouse and K/B won't put that controller into its highest bandwidth mode- "USB 2." Who want to bet that gigabyte was sloppy with their layout?

Copy a big file from/to that hard drive and I'll bet the speed is lousy or nonexistant.

This isn't a power issue, it's (lack of) bandwidth or suboptimal termination...
Gigabyte probably half-assed it, counting on people to only use their USB backplates- I'll bet the cable for that is -really- short.

-Paul

Edit:
CRC 2-26 or deoxit for oxidation, if you suspect any.

[b700029]

Re: Very strange problem with front panel usb ports

USB 2.0 (and 3.0) is very sensitive to things like impedance and wire lengths. If the data pair on the cable ends in long loose wires, try twisting them together for a few turns before plugging in to reduce EMI coupling.

[goodpsusearch]

Re: Very strange problem with front panel usb ports

Here are photos from the Gigabyte motherboard in question and the USB backplate that works.

[goodpsusearch]

Re: Very strange problem with front panel usb ports

The front panel USB of the cases that don't work with the Gigabyte motherboard...

[goodpsusearch]

Re: Very strange problem with front panel usb ports

And finally the black case's USB ports and cable that works.

I am unable to notice any difference between the "white" PC cases' USB and this..

[PCBONEZ]

Re: Very strange problem with front panel usb ports

Your Gigabyte adapter probably has shielded cable with a drain wire wrapped around the shield and attached to the ground wires.
Most case wires are just wire with no provisions for cross-talk. (That makes them USB 1 regardless of what the case ad claims.)

See pic.
That's what I was talking about before..
That often unused pin sometimes has a third ground wire connected to it in better quality USB parts.
.

[goodpsusearch]

Re: Very strange problem with front panel usb ports

Well, I think I found out something interesting.

1)The black case's front panel usb ports have their ground pins shorted.
The +5V pins are shorted too.
That should be the reason they work with the Gigabyte motherboard...

2)I tested 1 more PC case with front USB ports and they worked with the mobo. Guess what, the power pins are connected together again and so are the Ground cables.

3)And then I got for free a PC case with front USB ports that had only their grounds shorted, but not the 5Vs. That one sometimes worked and sometimes not and I got the unknown USB device message.

So, shorting together the power and ground cables is a cheap way to improve the signal or reduce the EMI???


edit: 4)The 3 identical cases with the USB ports that don't work with the Gigabyte motherboard don't have the ground cables neither the 5V shorted.

[ratdude747]

Re: Very strange problem with front panel usb ports

if the case has the ports on a PCB, you may be able to solder a small piece of wire to bridge the 5v and ground pins. if it is like a lot of newer OEM cases, then the ports are in a molded plastic shell and you are screwed