Kenwood KRK-14H, Руководство по обслуживанию

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(No.RA021<Rev.001>)1-13
Checking the output signal
from the MPU.
When an abnormal
value is confirmed.
When an abnormal
value is confirmed.
When an abnormal
value is confirmed.
When an abnormal
value is confirmed.
When an abnormal
value is confirmed.
When a normal
value is confirmed.
When a normal
value is confirmed.
When a normal
value is confirmed.
The LCD displays control
It is unlikely that the BGA parts are broken.
Points to be checked Normal voltage
3.3V
Points to be checked
Normal voltage
/FRST D13 (Anode side)
Points to be checked Normal voltage
/CS4 CP5 (8 pin)
After power-on, and
/CS4 has an abnormal voltage.
Check each of the following items.
Check to see the terminal of L43 and CP5.
Remove the FFC to Sub (Display) unit of the
NX-5700/5800 and KCH-19.
As a result, if the abnormality yet,
the MPU or Flash Memory or mobile DDR may
be broken.
Remove Q10.
If the MPU side is 3.3V,
the MPU or Flash memory or mobile DDR
may be broken.
Points to be checked Normal voltage
53DC C194 5.3V
The BGA parts are not broken.
Remove the FFC to Sub (Display) unit of the
NX-5700/5800 and KCH-19.
If the voltage becomes normal, the FFC or
Sub (Display) unit is broken.
The LCD displays “INIT ERROR 1”.
An error occurs when the mobile DDR internal
RAM reads or writes.
The mobile DDR may be broken.
Check the flowchart from beginning.
1) /PRST :MPU reset signal LOW Reset
2) /FRST :Flash Memory reset signal LOW Reset
3) /CS2_2 :Flash Memory chip select signal LOW Active
4) LCDRST :LCD reset signal LOW (L50 CN37 side) Reset
5) /CS_4 :LCD controller chip select signal LOW Active
Descriptions of signal names
If the /FRST is always 0V ,the MPU is broken.
Remove D13 to check the voltage of Flash
Memory side R167.
When a normal
value is confirmed.
Points to be checked Normal voltage
/CS2_2 CN31
After power-on,
and
1.8V
0V 1.8V,
1.8V fixed later
Remove R164.
When a normal
value is confirmed.
When an error display appears on the LCD
Checking the control signal output from the MPU.
18D C195
33D C201 1.8V
3.3V
1.8V
The LCD displays control
LCDRST
L50(CN37 side)
If the voltage of MPU side becomes 0V or 1.8V,
MPU is broken.
If the voltage of MPU side becomes normal,
Flash Memory or chip resistor(R164) may be broken.
When a normal
value is confirmed.
If the voltage becomes abnormal, Flash Memory
is broken.