Kenwood NX-5800 Service Manual page 107

Checking the output signal
from the MPU/DSP.
Checking the control signal output from
the MPU/DSP
Points to be checked Normal voltage
/FRST
D701(Anode side)
Points to be checked Normal voltage
/CS_FIC704(4 pin)
After power-on,
and
1.8V fixed later
Normal voltage
Points to be checked
SBC MPU/DSP side R51
The LCD displays control
Normal voltage
Points to be checked
54M C841
18M C839
33M C820
The LCD displays control
Normal voltage
Points to be checked
PRST
D801(Cathode side)
Points to be checked Normal voltage
/CS_LCD CP717 (8 pin) After power-on
and
1.8V fixed later
It is unlikely that the BGA parts are broken.
When an error display appears on the LCD.
The LCD displays "INIT ERROR 1".
Descriptions of signal names
(1) /RST :MPU/DSP reset signal
(2) /BINT :Battery final voltage monitoring
(3) /OVRB_OUT :Battery overvoltage monitoring
(4) /PSW_OUT :Power switch signal
(5) /IGN_OUT :Ignition switch signal
(6) /FRST :Flash Memory reset signal
(7) /CS_F :Flash Memory chip select signal
(8) SBC :Switch +B control
(9) 30LCD :LCD module control 3.0V power supply
(10) PRST :LCD reset signal
(11) /CS_LCD :LCD controller chip select signal
When an abnormal
value is confirmed.
1.8V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
When a normal
value is confirmed.
When an abnormal
value is confirmed.
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
5.36V
1.8V
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
When a normal
value is confirmed.
LOW Reset
LOW Final voltage
LOW Overvoltage
LOW ON
LOW ON
LOW Reset
LOW Active
HIGH ON
LOW Reset
LOW Active
If the /FRST is always 0V, the MPU/DSP
is broken.
Remove D701 to check the voltage of
Flash memory side R732.
If the voltage becomes abnormal, Flash
memory is broken.
If the IC704 (1 pin) is 0V or 1.8V,
the MPU/DSP may be broken.
If the IC704 (2 pin) is 0V or 1.8V,
the MPU/DSP or Flash memory may be
broken.
Remove R51 to check the voltage of the SBC.
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 the FFC of Main unit between
Sub (Display) unit.
If the voltage becomes normal, the FFC or
Sub (Display) unit is broken.
Remove Q703.
If the MPU/DSP side is 3.3V, the MPU/DSP
or Flash memory or mobile DDR may be
broken.
/CS_LCD has an abnormal voltage.
Check each of the following items.
Check to see the terminal of L731 and
CP717.
Remove the FFC of Main unit between
Sub (Display) unit.
As a result, if the abnormality yet, the
MPU/DSP or Flash memory or mobile DDR
may be broken.
An error occurs when the mobile DDR
internal RAM reads or writes.
The mobile DDR may be broken.
Check the flowchart from beginning.
(No.RA017<Rev.003>)1-107