(No.RA070<Rev.001>)1-57
SECTION 5
TROUBLESHOOTING
5.1
Fault Diagnosis of the BGA (Ball Grid Array) IC
Overview
A flowchart for determining whether or not the transceiver can be powered on (the Transceiver does not function (No LCD display, No
power on beep or other) even if the power switch is turned on) due to broken BGA parts.
BGA parts
MPU/DSP(IC401), mobile DDR(IC402), Flash Memory(IC404)
When the BGA IC is problematic, it is necessary to replace the printed circuit board by the Service Main unit in service. Various ESN/
default adjustment values are written on the service unit. Please refer to "5.6 Replacing Main Unit".
Checking power supply voltage
Checking voltage
Points to be checked
Points to be checked
(1.2V)
Points to be checked
Points to be checked
Normal voltage
Normal voltage
Normal voltage
1.2V
19.2MHz
12M C32
1.8V
18M C24
3.2V
1.8V
3.2V
32M IC5(1pin)
1.8V
18M_3 IC12(1pin)
Power supply of each device is connected through the coil.
[MPU/DSP]
12M: L404, L405, L406
18M: L407, L408
32M: R452
[mobile DDR]
18M: L409
[Flash Memory]
32M: R451
18M_3: L410
Checking the clock
Checking the clock
Normal voltage
1.2V(peak-to-peak)
19.2MHz
MPU/DSP side R410
Pass
Pass
Pass
Pass
Checking the Reset/Control signal
Checking the control signal input to the MPU/DSP
/RST IC403 (4pin)
/BINT Q3 (6pin)
Checking the control signal output from the MPU/DSP
If the /FRST is always 0V, the MPU/DSP is broken.
The BGA parts are not broken.
Checking for an abnormal point
12M has an abnormal voltage.
[MPU/DSP]
Remove L404 and L405 and L406 to check the
voltage of the 12M.
.If the voltage becomes normal, the MPU/DSP
is broken.
18M has an abnormal voltage.
[MPU/DSP]
Remove D402 to check the voltage of Flash
Memory side R445.
Fail
Fail
Fail
Fail
/FRST
Checking battery voltage
Points to be checked voltage
Normal voltage
6~9V
+B CN3
The BGA parts are not broken.
If the CN3 is less than 6V, charge the battery.
Fail
Pass
/PSW Q2 (3pin)
3.2V
Flash memory side D402
1.8V
Remove L407 and L408 to check the voltage
of the 18M.
If the voltage becomes normal, the MPU/DSP
is broken.
[mobile DDR]
Remove L409 to check the voltage of the 18M.
If the voltage becomes normal, the mobile
DDR is broken.
32M has an abnormal voltage.
[MPU/DSP]
Remove R452 to check the voltage of the 32M.
If the voltage becomes normal, the MPU/DSP
is broken.
[Flash memory]
Remove R451to check the voltage of the 32M.
If the voltage becomes normal, Flash Memory
is broken.
If the voltage is not corrected, there is a problem
other than the BGA parts.
If the voltage becomes abnormal, Flash Memory
is broken.
18M_3 has an abnormal voltage.
[Flash memory]
Remove L410 to check the voltage of the 18M_3.
If the voltage becomes normal, Flash Memory
is broken.
