HP dc7800 manual System Board Component Designations

Power and Signal Distribution

Table 7-7. (Continued)

System Board Component Designations

SW50	Clear CMOS switch
XMM1	Memory slot (black)
XMM2	Memory slot (white)
XMM3	Memory slot (white)	SFF & CMT only
XMM4	Memory slot (white)	SFF & CMT only
XU1	Processor socket
XB2	Battery socket

Figure 7-6 shows pinouts of headers used on the sytem boards.

Power Button/LED, HD LED	Power Button/LED, HD LED
Header P5 (USDT, SFF)	Header P5 (CMT)

HD LED + 1

HD LED - 3

GND5

Pwr Btn 7

Chassis ID0 9

GND 11

Therm Diode A 13

2 PS LED +

4 PS LED -

8 GND

10 Chassis ID1

12 NC

14 Therm Diode C

HD LED Cathode 1

HD LED Anode 3

GND5

M Reset 7

+5 VDC 9

NC 11

GND 13

Chassis ID2 15

Chassis ID0 17

2 PS LED Cathode

4 PS LED Anode

6 Pwr Btn

8GND 10 NC 12 GND

16 +5 VDC

18 Chassis ID1

Front Panel Audio

Header P23

Mic In Left (Tip) 1

Mic In Right (Sleeve) 3 HP Out Right 5

Sense Send 7

HP Out Left 9

2 Analog GND

4 Front Audio Detect#

6 Sense_1 Return

10 Sense_2 Return

Serial Port A	Serial Port B
Header P54	Header P52

UART1 DCD- 1

UART1 RX DATA 3

UART1 TX DATA 5

UART1 DTR 7

GND 9

2UART1 DSR-

4 UART1 RTS-

6 UART1 CTS-

8 UART1 RI-

10 Comm A Detect-

UART2 DTR- 1

UART2 CTS- 3

UART2 TX DATA 5

GND 7

+5.0V 9

UART2 RTS- 11

UART2 DCD- 13

+12V 15

2 UART2 RX DATA

4 UART2 DSR-

6UART2 RI-

8GND

10 +3.3V aux

12 Comm B Detect

14 -12V

Hood Lock

Header P124

Hood Lock 1		2 Coil Conn
		4 +12V
	GND 5	6 Hood Unlock

Hood Sense

Header P125

1 Hood SW Detect

2GND

3Hood Sensor

NOTE:

No polarity consideration required for connection to speaker header P6.

NC = Not connected

Figure 7-6. System Board Header Pinouts

Technical Reference Guide www.hp.com 7-11