Troubleshooting; Fault Diagnosis Of The Bga (Ball Grid Array) Ic - Kenwood NX-3220 K Service Manual

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 LCD does not function even if the power switch is
turned on) due to broken BGA parts.
BGA parts
MPU/DSP(C401), mobile DDR(IC402), Flash Memory(IC404)
Checking battery voltage
Points to be checked voltage
+B CN3
Checking power supply voltage
Checking voltage
Points to be checked
12M C32
18M C24
32M IC5(1pin)
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
Points to be checked
(1.2V)
19.2MHz
MPU/DSP side R410
Checking the Reset/Control signal
Checking the control signal input to the MPU/DSP
Points to be checked
/RST IC403 (4 pin)
/BINT Q3 (6 pin)
/PSW Q2 (3 pin)
Checking the control signal output from the MPU/DSP
Points to be checked
/FRST
Flash memory side D402
SECTION 5

TROUBLESHOOTING

Normal voltage
Fail
6~9V
Pass
Fail
Normal voltage
1.2V
1.8V
3.2V
1.8V
Pass
Normal voltage
Fail
1.2V(peak-to-peak)
19.2MHz
Pass
Fail
Normal voltage
1.8V
3.2V
3.2V
Pass
Fail
Normal voltage
1.8V
Pass
The BGA parts are not broken.
If the CN3 is less than 6V, charge the battery.
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 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.
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.
If the voltage is not corrected, there is a problem
other than the BGA parts.
The BGA parts are not broken.
If the /FRST is always 0V, the MPU/DSP is broken.
Remove D402 to check the voltage of Flash
Memory side R445.
If the voltage becomes abnormal, Flash Memory
is broken.
(No.RA053<Rev.001>)1-149