NEC NP-NC900C-A Service Manual page 27

J10 To Fan Driver BD – E (CN9820)
Note: Pin to Pin
12V
12V
GND
5V
GND
I2C_SCL
I2C_SDA
FAN_Driver BD_Flag
–
–
–
J17 To Ballast 1 Control Interface
Note: Pin to Pin
TXD
GND
3.3V
SCI/Lampsync
RXD
J18 To Ballast 2 Control Interface
Note: Pin to Pin
TXD
GND
3.3V
SCI/Lampsync
RXD
–
J11 NTC1
DC Voltage
3V3
J12 NTC2
DC Voltage
–
3V3
J28 Tamper Switch
TAMP0_1
GND
SD_NO_TAMPER_O
"Confidential, Do Not Duplicate without written authorization from NEC."
TROUBLESHOOTING
1
g 12V Output
2
3 – GND
g
4 5V Output
5 – GND
6 g
I2C communication between uC BD and Fan Driver BD
7 n
If FAN actual RPM is out of the programmed value, ALERT pin
8 f
goes low.
9 – –
10 – –
11 – –
1 f Ballast UART Interface.
2 – GND
3 g Ballast Control Interface Power Source
4 g Lamp Lit input/Lamp sync input
5 g Ballast UART Interface.
f
1 Ballast UART Interface.
2 – GND
3 g Ballast Control Interface Power Source
4 g Lamp Lit input/Lamp sync input
5 g Ballast UART Interface.
6 – –
1 f Per the temperature.
Normal: 3V3/Other voltage: SLAVE uC BD 3V3 suppling is
f
2
something wrong.
1 g Per the temperature.
2 – –
Normal: 3V3/Other voltage: SLAVE uC BD 3V3 suppling is
f
3
something wrong.
When the Tamp. Switch is pressed, it is Lo status. (Normal, no
1 f
issue) Unpressed, it is Hi status. (NG, 4.5V +/- 5%)
2 – –
Notice!! This pin is connected to a battery.
3 g
Don't measure this line by any equipment in board slot-in condition.
4-17