Fan power connector (cn3), Smbus connector (cn4), Power led header (cn6) – Axiomtek PICO841 User Manual
Page 22: External speaker and internal buzzer header (cn7), 2 fan power connector (cn3), 3 smbus connector (cn4), 4 power led header (cn6)

PICO841 Intel
®
Atom
TM
Processor E3845/E3827 Pico-ITX Board
16
Board and Pin Assignments
2.5.2
Fan Power Connector (CN3)
This is a JST B2B-ZH-K-S 1.5mm pitch wafer connector for fan power interface.
2 1
2.5.3
SMBus Connector (CN4)
This connector is for SMBus interface. The SMBus (System Management Bus) is a
simple 2-wire bus for the purpose of lightweight communication.
2.5.4
Power LED Header (CN6)
This header is for power LED interface.
2.5.5
External Speaker and Internal Buzzer Header (CN7)
Pin 1, 2 and 3 connect the case-mounted speaker unit or internal buzzer. While
connecting the CPU board to an internal buzzer, please set pin 2 and 3 closed (default);
while connecting to an external speaker, you need to set pins 2 and 3 opened and
connect the speaker cable to pin 1(+) and pin 2(-).
1 3
Pin
Signal
1
+5V
2
GND
Pin
Signal
1
SMBus clock
2
SMBus data
3
GND
Pin
Signal
1
+5V
2
GND
Pin
Signal
1
EXT SPK+
2
EXT SPK-
3
Buzzer