Installing and Replacing Desktop Board Components 
45 
Front Panel Audio Header 
The front panel audio header shown in Figure 20, A supports both Intel High Definition 
(HD) Audio and AC ’97 Audio.  
Table 5 shows the pin assignments and signal names for
 HD Audio and Table 6 shows 
the pin assignments and signal names for AC ’97 Audio. 
Table 5.  Front Panel Audio Signal Names for Intel HD Audio  
Pin Signal Name  Pin Signal Name 
1   PORT 1L (Microphone)  2  GND 
3  PORT 1R (Microphone)  4  PRESENCE# 
5  PORT 2R (Headphone)  6  SENSE1_RETURN 
7 SENSE_SEND  8 KEY (no pin) 
9  PORT 2L (Headphone)  10  SENSE2_RETURN 
 
Table 6.  Front Panel Audio Header Signal Names for AC ’97 Audio  
Pin Signal Name  Pin Signal Name 
1   MIC  2  AUD_GND 
3 MIC_BIAS  4 PRESENCE# 
5 FP_OUT_R  6 AUD_GND 
7  No connect  8  KEY (no pin) 
9 FP_OUT_L  10 AUD_GND 
 
Chassis Intrusion Header 
Figure 20, B shows the location of the chassis intrusion header.  This header can be 
connected to a mechanical switch on the chassis to detect if the chassis cover is 
removed.  This switch should be in the open position when the chassis cover is 
installed and closed when the cover is removed.  
Table 7 shows the pin assignments and
 signal names for
 the chassis intrusion header. 
Table 7.  Chassis Intrusion Header Signal Names 
Pin Description 
1   Ground  
2 Intruder#