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"COM" connector on Case front panel USB?

post #1 of 6
Thread Starter 
I took apart this Compaq Presario 5000 case with 2 usb ports in the front.

I swapped out all the parts running a amd athlon 64 x2, etc in it and the front panel has 2 usb ports.

The usb connector is a "COM" connector, not the typical USB connector, maybe it's because of usb 1.0 or 1.1? Its old school as we know.

I just want to get the usb ports working...

Can someone explain why the USB ports have a COM connector? I plugged it in the COM port on the ASUS A8R-MX/SI motherboard and they don't work.









Thanks
Edited by chris89 - 10/2/13 at 9:08am
post #2 of 6
    I'm not sure what you mean by "COM" connector on the USB cable.  Many older motherboards do have a "COM" pin header for a second RS232 serial port in addition to having pin header(s) for front USB.  The COM (Serial), 1394 (Firewire) and USB pin headers can look very similar on a motherboard.  But since only a USB header will work with USB, you will need to find a pin header on the motherboard labled "USB" or "Front USB" or "USB2" to plug your front USB connector into.

    The connector for your front USB jack looks normal to me.  If you can't find a USB pin header on the motherboard, post a full resolution photo of the motherboard here.  If you installed a different motherboard into Presario case, there is a small possibility that the motherboard you installed doesn't have a pin header for front USB, and its USB jacks are on the back panel instead. thumb.gif

    Just so you know: The connections for USB have remained unchanged (+5v, Gnd, two signal lines, and maybe a shield) until USB 3.
 
Edited by Techie007 - 10/2/13 at 11:07am
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post #3 of 6
Thread Starter 
Quote:
Originally Posted by Techie007 View Post

    I'm not sure what you mean by "COM" connector on the USB cable.  Many older motherboards do have a "COM" pin header for a second RS232 serial port in addition to having pin header(s) for front USB.  The COM (Serial), 1394 (Firewire) and USB pin headers can look very similar on a motherboard.  But since only a USB header will work with USB, you will need to find a pin header on the motherboard labled "USB" or "Front USB" or "USB2" to plug your front USB connector into.

    The connector for your front USB jack looks normal to me.  If you can't find a USB pin header on the motherboard, post a full resolution photo of the motherboard here.  If you installed a different motherboard into Presario case, there is a small possibility that the motherboard you installed doesn't have a pin header for front USB, and its USB jacks are on the back panel instead. thumb.gif

    Just so you know: The connections for USB have remained unchanged (+5v, Gnd, two signal lines, and maybe a shield) until USB 3.
 

As you can see in the many photos above that the USB header has a COM or SERIAL port. You can tell by comparing the connectors.




This is what the board looks like, where you can clearly see the COM port on the bottom right followed by a few usb headers.


Edited by chris89 - 10/2/13 at 11:26am
post #4 of 6
    I think I see what you're saying.  USB header connectors are normally flat, without any guiding edges and grooves, while the COM header connectors usually have a grooved plug that fits into a plastic retainer socket on the motherboard.  Just ignore the looks of the connector, and plug it into one of the USB headers on the motherboard.  Both the COM header and USB headers share the same number of pins, with the same missing polarizer pin.  Don't worry that it is a perfect fit to plug the USB connector into the COM header on the motherboard, because that certainly won't work!

    If you're concerned, I suggest for the first time to plug something cheap (like a USB mouse or keyboard) into each of those USB connectors in turn just to make sure that the connections are correct. thumb.gif
 
Edited by Techie007 - 10/2/13 at 11:30am
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post #5 of 6
Thread Starter 
Quote:
Originally Posted by Techie007 View Post

    I think I see what you're saying.  USB header connectors are normally flat, without any guiding edges and grooves, while the COM header connectors usually have a grooved plug that fits into a plastic retainer socket on the motherboard.  Just ignore the looks of the connector, and plug it into one of the USB headers on the motherboard.  Both the COM header and USB headers share the same number of pins, with the same missing polarizer pin.  Don't worry that it is a perfect fit to plug the USB connector into the COM header on the motherboard, because that certainly won't work!

    If you're concerned, I suggest for the first time to plug something cheap (like a USB mouse or keyboard) into each of those USB connectors in turn just to make sure that the connections are correct. thumb.gif
 

Thanks bro I appreciate your input.

The connectors don't have the same missing polarized pin.

The front panel usb for some reason has a SERIAL or COM connector which is so weird...

Maybe it's USB header with the same exact configuration as COM/ Serial.

The missing pin on SERIAL or COM is the TOP RIGHT. The missing pin on the USB is BOTTOM RIGHT. So it won't plug in no matter what.

COM or SERIAL HEADER

USB HEADER

Here is a Close-Up

Edited by chris89 - 10/2/13 at 12:09pm
post #6 of 6
    EDIT: Thanks to your ever improving pictures and diagrams, I see that the wrong pin is blanked out.  I think I encountered a computer like that, and I just drilled out the offending plugged pin so that I could plug the connector in.  That was a long time ago.  I don't remember whether it worked or not.  There may be more pinout issues, and with the COM style connector, you can't pop the pin sockets out of the connector and reconfigure them like you can on the modern USB header connectors.  Perhaps somebody else here has more recent experience with this. thumb.gif
 
Edited by Techie007 - 10/2/13 at 11:48am
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Kingston SV300S3 WesternDigital WD10EZEX Samsung HD154UI Windows 7 Ultimate SP1 x64 
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