View Full Version : USB wiring colour code

28-02-2009, 06:42 PM
I have non standard USB wiring colour with my front 2 x USB ports. They are black, green, yellow, red for one. Red, white, blue, black for the second. I'm fitting up a new motherboard into an existing older chassis. It all looks in order with connectors marked 5+, ground, D+ D-. Is there any cause for caution? Could it be for USB 1.1 sockets? As it's an all new mobo I'm a bit hesitant to connect. Thanks. Will upload photo if needed.

28-02-2009, 06:45 PM
Have you checked your manual?

28-02-2009, 07:55 PM
Yes. The manual doesnt state colour codes but it only covers the mobo. There is no manual for the case and front USB.
Wiki tells me the colours are red, white, green, black.
For all I know colour variation could be a normal phenomena between manufacturers?

28-02-2009, 08:00 PM
Are the ends of the wires from your case marked with the appropriate markings? (i.e. 5+, ground etc.)

If they are, then you'll be safe simply plugging them into the appropriate header on your motherboard. Being USB1.1 vs 2.0 won't be any problem, as the connectors are the same.

28-02-2009, 08:05 PM
You don't go by colour, you go by the markings which your manual will state.

28-02-2009, 08:26 PM
If I go by markings I believe it's OK.Thanks.

01-03-2009, 01:35 AM
I'm not sure that there are any standard colours for USB ports.

But the pin names certainly are standard (5V+, D+, D-, GND) - or similar.

If you want to be paranoid, get a multimeter and trace each pin to the USB port itself.

BUT DO NOT have the power on while doing this. It's very easy to short the 5V line to GND and burn traces on your motherboard. All PSU now supplies USB ports with 5V Standby even when the PC is turned off. You must make sure the PSU is unplugged completely, in the event the motherboard routes power from 5VSB.

USB 1.0/1.1/2.0 are all the same pinout. It's USB 3.0 that's going to be a little different...

Speedy Gonzales
01-03-2009, 09:28 AM
On the other PC here

Red - +5
White -D
Blue +D
Black is always GND


Red +5
Yellow -D
Green +D
Black - GND

If the connector is just one block/connector, not separate, just make sure black on both, are connected to GND on the mobo USB header

Also, make sure if the mobo has firewire headers, DO NOT connect USB cables to it. Or vice-versa.

You'll kill the motherboard

01-03-2009, 01:28 PM
Thanks for that, I'm learning a lot!
I'm exceedingly grateful to you guys for sharing your hard earned knowledge.

On a funny note...
I checked the back of the USB ports themselves and discovered to my amazement, that the multi-pin connector was not oriented properly on the pins. IE. it was shifted across a complete row as it were. It's just as well I never plugged the other end into the mobo before finding that. No doubt that was why the leads were all knotted up & sitting unconnected from the board I removed!!