Installing and Replacing Desktop Board Components 
49 
Alternate Front Panel Power LED Header 
Figure 21, G on page 45 shows the location of the alternate front panel power LED 
header.  Pins 1 and 3 of this header duplicate the signals on pins 2 and 4 of the front 
panel header.  If your chassis has a three-pin power LED cable, connect it to this 
header.  
Table 13 shows the pin assignments for the al
ternate front panel power LED header. 
Table 13. Alternate Front Panel Power LED Header 
Pin Description  In/Out 
1   Front panel green LED  Out 
2 No pin   
3  Front panel yellow LED  Out 
 
USB 2.0 Headers  
Before connecting to the USB 2.0 headers, observe the precautions in "Before You 
Begin" on page 27.  See Figure 21, H on page 45 for the location of the three USB 2.0 
headers.  Table 14 shows the pin assignments for each USB 2.0 
header.  Each USB 
header can be used to connect two USB devices. 
Table 14. USB 2.0 Header Signal Names  
USB Port A  USB Port B 
Pin  Signal Name  Pin  Signal Name 
1  Power (+5 V)  2  Power (+5 V) 
3 D-  4 D- 
5 D+  6 D+ 
7 Ground  8 Ground 
9 Key  10 No Connection 
Note:  USB ports may be assigned as needed. 
 
 
NOTE 
Computer systems that have an unshielded cable attached to a USB port might not 
meet FCC Class B requirements, even if no device or a low-speed USB device is 
attached to the cable.  Use a shielded cable that meets the requirements for a 
full-speed USB device.