Descriptions Of Signal Names - Kenwood NX-5400 Service Manual

Checking the output signal
from the MPU/DSP.
Points to be checked
/CS_F IC706 (4 pin)
Points to be checked
SBC MPU/DSP side R21
The LCD displays control
Points to be checked
30M IC80 (1 pin)
Points to be checked
/RESET (LCD_RST)
CN9 (11 pin)
Points to be checked
/CS4 CN9 (10 pin)
It is unlikely that the BGA parts are broken.
When an error display appears on the LCD
The LCD display "INIT ERROR".
1) /RST : MPU/DSP reset signal
2) /BINT : Battery final voltage monitoring
3) /PSW : Power switch signal
4) /FRST : Flash memory reset signal
5) /CS_F : Flash memory chip select signal
6) SBC : Switch +B control
7) 30M : LCD module control 3.0V power supply
8) /RESET (LCD_RST) : LCD reset signal
9) /CS4 : LCD controller chip select signal
When a normal
value is confirmed.
When an abnormal
Normal voltage
value is confirmed.
After power-on, and
1.8V 0V 1.8V,
1.8V fixed later
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.0V
When a normal
value is confirmed.
When an abnormal
Normal voltage value is confirmed.
1.8V
When a normal
value is confirmed.
When an abnormal
Normal voltage
value is confirmed.
After power-on, and
1.8V 0V 1.8V,
1.8V fixed later
When a normal
value is confirmed.
If the IC706 (1 pin) is 0V or 1.8V, the MPU/DSP
may be broken.
If the IC706 (2 pin) is 0V or 1.8V, the MPU/DSP
or Flash memory may be broken.
Remove the following parts.
C47
R21
R39
R66
Q32
IC36
IC61
If the MPU/DSP side is 0V, the MPU/DSP or
Flash memory or mobile DDR may be broken.
The BGA parts are not broken.
Remove R867 to check the voltage of the 30M.
If the voltage becomes normal, re-insert the
FPC of LCD module or replace the LCD module.
Remove Q800.
If the MPU/DSP side is 3.3V,
the MPU/DSP, Flash memory or mobile DDR
may be broken.
/CS4 has an abnormal voltage.
Check each of the following items.
Check to see the terminal of L802.
Re-insert the FPC of LCD module.
Replace the LCD module.
As a result, if the abnormality yet, the MPU/DSP
of Flash memory of mobile DDR may be broken.
An error occurs when the mobile DDR internal
RAM reads or writes.
The mobile DDR may be broken.
LOW Reset
LOW Final voltage
LOW ON
LOW Reset
LOW Active
HIGH ON
LOW Reset
LOW Active
(No.RA016<Rev.001>)1-65