Troubleshooting - Kenwood NX-5300 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 (IC702), mobile DDR (IC703), Flash memory (IC705)
When the BGA IC is problematic, please bring the printed circuit board (XC1-0341-82/XC1-0341-83) in for service. Various ESN/
default adjustment values are written on the printed circuit board for service.
Additionally various ESN stickers are included. (Please refer to "5.4 Replacing Main Unit".)
After the printed circuit board has been readjusted, please attach any ESN stickers to the chassis. When "ESN Validation" is used,
you must modify the ESN register.
Checking battery voltage
Points to be checked
+B CN2
Checking power supply voltage
Checking voltage
Points to be checked
12M C51
18M IC43
33M IC35 (1 pin)
18M_3 IC701 (1 pin)
Power supply of each device is connected through the coil.
[MPU/DSP]
12M: L705, L706, L708
18M: L710, L711
33M: L712
[mobile DDR]
18M: L717
[Flash Memory]
33M: L718
18M_3: L719
Checking the clock
Checking the clock
Points to be checked
19.2MHz
MPU/DSP side R780
Checking the Reset/Control signal
Checking the control signal input to the MPU/DSP
Points to be checked
/RST IC704 (4 pin)
/BINT Q22 (6 pin)
/PSW Q21 (3 pin)
Checking the control signal output from the MPU/DSP
Points to be checked
/FRST
Flash memory side D705
SECTION 5

TROUBLESHOOTING

When an abnormal
Normal voltage
value is confirmed.
6~9V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
1.2V
1.8V
3.3V
1.8V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage (1.2V)
19.2MHz
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
1.8V
3.3V
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
1.8V
When a normal
value is confirmed.
The BGA parts are not broken.
If the CN2 is less than 6V, charge the battery.
Checking for an abnormal point
12M has an abnormal voltage.
[MPU/DSP]
Remove L705, L706 and L708 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 L710 and L711 to check the voltage
of the 18M.
If the voltage becomes normal, the MPU/DSP
is broken.
[mobile DDR]
Remove L717 to check the voltage of the 18M.
If the voltage becomes normal, the mobile
DDR is broken.
33M has an abnormal voltage.
[MPU/DSP]
Remove L712 to check the voltage of the 33M.
If the voltage becomes normal, the MPU/DSP
is broken.
[Flash memory]
Remove L718 to check the voltage of the 33M.
If the voltage becomes normal, Flash memory
is broken.
18M_3 has an abnormal voltage.
[Flash memory]
Remove L719 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 D705 to check the voltage of the Flash
memory side R747.
If the voltage becomes abnormal, Flash memory
is broken.
(No.RA015<Rev.002>)1-105