A. Those of us who make our own machines or simply need to change a component often have cables from computer cases that need to be connected to the motherboard, and some of these cables must be connected a particular way based on the plus and minus signs. If you look at the various cables, one wire will be solid colored and one will be white, sometimes with color stripes. The colored cable is positive, so always place it into the plus pin on the motherboard, as shown below. If there's no plus or minus on the pins, the cable can be connected either way, as is the case with power and reset switches.

Click to expand

If you get the cables the wrong way round on the LEDs, the only problem you'll have is that the LEDs won't light up. It's hard to actually cause damage.

Related Reading:
Check out hundreds more useful Q&As like this in John Savill's FAQ for Windows. Also, watch instructional videos made by John at ITTV.net.