USB Header issue... any one have idea ?

[WarhammerUC]

I have a motherboard that uses usb s-gnd pin for the front usb header. In my new case, the built in front usb header does not have a usb s-gnd.. so the front usb does not turn on. Is there anyway to mod the usb pins to supply the usb s-gnd ?

USB S-gnd : http://www.frontx.com/cpx108_2.html

Case: COOLER MASTER RC-690-KKN1-GP

 

[Zepper]

In most cases the front panel USB cables bond the shield drain and the signal ground to the same wire so a separate shield ground pin on the mobo isn't needed - should work fine without it.

I got a 690 today and the front panel USB cables do have the signal ground and drain bonded. Many mobos have a pin in the 9th place but it's not connected to anything on the mobo - on some mobos that extra pin is connected to ground. All ground pins on the mobo are connected together so as long as the shields are grounded (best if at both ends, but one will do - just noting that the front-panel PCB isn't connected to ground either) it will work fine. If yours aren't working then either something else is wrong with the cables or the ports themselves. Often have to make sure the front panel wiring is OK with an Ohm meter or Multi meter as they are assembled so cheaply.

But on my 690 the shield wire on the FW cable is not connected to chassis metal. It was connected to one of the plastic risers that supports the front panel PCB. There is a nearby hole in the chassis that it should be connected to using a self-tapping (or sheet metal) screw - a machine screw and wing nut would do just as well. That should have no effect on the USB cables at all though.

.bh.

I just pulled the front panel PCB to take a closer look - not sure yet whether the PCB needs to be grounded as well. .bh.

 

[WarhammerUC]

Thanks... so how do you like the case so far ?

BTW do you use any of the top 2 120mm fan ? intake or exhaust ? Right now i have it on exhaust.. i think they probably work better as intake ? suck in fresh air for the cpu fan to push out the rear ?

 

[Zepper]

Initially I'll just be using the front and rear fans (one each). I'll block off all other superfluous venting with a couple layers of Saran Wrap and/or clear packaging tape (including the holes above the PCI slots) as all those vents just short-circuit any careful airflow planning - air comes in and goes out w/o having done any significant cooling work.

I'll add some back perhaps as I see it's needed. First I'll have to add back is probably the bottom fan for intake and that will use up the three stock fans. I can't imagine needing more than that.. If it comes to pass that I need more cooling, I'll probably add a more powerful fan in the strategic location where one of the three already exists.

Top mounted fans (blow holes) have seldom if ever been shown to be of much use.

.bh.