VOGONS


First post, by EdmondDantes

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So I had two comps that didn't recognize front USB ports even when said ports were hooked up to the motherboard. One was my Epox-8KTA board, which I thought this behavior was normal since that board was so old (and it was running Win98SE anyway) but recently it happened again on that Dell GX260 I have which was unusual because, for awhile, it saw front USB panels just fine, but then suddenly it stopped seeing them.

Now, the front panel is hooked up with one of these doohickeys which you'll see also has a headphone jack.... the headphone jack works just fine, but the USB ports do not.

I've tried XP and a version of Linux which has always recognized these USB ports before, completely disconnecting my current hard drive to make sure its not the OS (actually rehooking up a different HD which had an XP install where the ports worked). So I'm convinced its a BIOS problem.

The only thing I can think is... when I got this Dell its bios version was A05, I upgraded it to A06 and I'm suspecting that might have something to do with the issue, but I dunno how to revert back to A05.

As for options in the BIOS... the only BIOS screens that seem relevant are... one lets you select whether USB ports (and an option for emulation) are on at all (in my case, both ARE, though I've deactivated the emulation one before just to test) and another one that lets you select what IRQ settings they use (a few of them are, for reasons unknown to me, forced to share their IRQ with my video and sound card--when I change them it automatically makes those match--so I'm not sure what the deal is, but this has always been the case.

Those are the only two parts of the Dell GX260's setup that mention USB at all.

Anyway, this is more of a curiosity rather than a real issue, since I found a workaround (plugging an extension cord into one of the back USB ports and keeping the other end up front, since the ones on the back *always* work) but it just bothers me that the front jacks used to work and now don't and I see no logical cause for it.

Reply 1 of 6, by Kahenraz

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It's possible that there is a second cable that connects to the pins on the back of the little board and to a USB header on the board. I can see some pins in that photo.

It won't be a USB header unless there is a missing pin to account for the key pin. Google "usb motherboard key" to see what it looks like.

Reply 2 of 6, by derSammler

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It won't be a USB header unless there is a missing pin to account for the key pin.

Older mainboards had no key pin on the USB header. Before, there were even two different pin-outs for the header and the key pin was added when the pin-out was normalised.

Reply 3 of 6, by Errius

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That's right, I've had to bend pins out of the way to connect newer USB cables to some older hardware.

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Reply 4 of 6, by Repo Man11

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derSammler wrote:

It won't be a USB header unless there is a missing pin to account for the key pin.

Older mainboards had no key pin on the USB header. Before, there were even two different pin-outs for the header and the key pin was added when the pin-out was normalised.

Some older motherboards. My Asus TXP4 and P55T2P4 both have standard layout nine pin USB headers on them. But other AT boards I've had used proprietary setups that required a volt meter to be sure you were getting the right wire on the right pin. I had a Chaintech 5AGM2 that had tiny USB pins - the only thing I found to fit them (since I did not have, and wasn't going to buy, Chaintech's expensive USB adapter) were some tiny five pin connectors salvaged out of a dead CDROM. I had to trim these to fit, then solder the wires to a standard USB adapter. This sort of difficulty with I/O is a major reason why ATX became the runaway standard after it was introduced.

Reply 5 of 6, by wiretap

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Also be aware of some boards that have a non-standard USB header pinout. It looks the same as a modern layout, but the pin assignments are switched around, and sometimes even reversed on the opposite row. I had to re-pin my front panel USB connector to work with my Abit VT6X4 motherboard.

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Reply 6 of 6, by EdmondDantes

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My Dell GX260 mobo has a unique pin layout--there is just one big rectangle marked "front panel" which you plug a single cable (its similar to how IDE cables work) with all the front panel stuff into. That's what's making it weird for me as I can't possibly see how I could've "forgotten to plug something in" when by design, you plug everything in at once.

The doohickey in question takes up the full front panel connector. I'm gonna check and make sure I didn't plug it in backwards or something. But again its weird, because I would think if I didn't then none of the front panel stuff would work, but again the speaker jack works, and they're on exactly the same green PCB thing as the USB ports.

On my Epox-8KTA, I always plugged the clearly marked "front USB" cables into the part of the motherboard that, again, is clearly marked "front USB," but they still never worked. But that's the board that I mentioned a month ago turned out to have bad caps so maybe that's why those didn't work. The Dell is considerably more of a mystery to me.