NEC NP-NC900C-A Service Manual page 31

1-3-3. PWM Fan Driver Board – B side
PWM Fan Driver BD -B side
J9850 From SLAVE uC BD (J7)
Note: Pin to Pin
12V
12V
GND
5V
GND
I2C_SCL
I2C_SDA
FAN_Driver BD_Flag
"Confidential, Do Not Duplicate without written authorization from NEC."
TROUBLESHOOTING
J9850
1
f 12V Input
2
3 – GND
4 f 5V Input
5 – GND
6 f
I2C communication between uC BD and Fan Driver BD
n
7
If Fan actual RPM is out of the programmed value, ALERT pin
8 g
goes low.
4-21
J9852
J9851