Trouble Shooting - Kenwood NX-300 Service Manual

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
ASIC (IC108), DSP (IC719), FLASH (IC101), SRAM (IC103)
When the BGA IC is problematic, please bring the printed circuit board (XC1-0020-12 for 6-key, XC1-0020-13 for 18-key) 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 pages 43 and 44.)
Button type lithium battery (W09-0971-05) does not belong to the printed circuit board for service. Please use the part which
has been attached to the printed circuit board. After the printed circuit board has been readjusted, please attach any ESN
stickers to the chassis. When "ESN Validation" is used with NXDN Trunking, you must modify the ESN register.
G Checking power supply voltage
Checking voltage
Points to be checked
33M IC404 (3 pin)
15M IC717 (4 pin)
33A IC406 (5 pin)
31BU IC416 (3 pin)
Power supply of each device is connected through the coil.
[ASIC]
33M: L714, 15M: L715, 33A: L716
[DSP]
33M: L712, 15M: L711
[FLASH]
33M: L717
[SRAM]
31BU: L710
G Checking the clock
Checking the clock
Points to be checked
18.432MHz ASIC side R158
ASIC & DSP side R159
32.768kHz IC106 (1 pin)
G Checking the Reset/Control signal
Checking the control signal input to the ASIC
Points to be checked
RESET IC105 (4 pin)
/BINT Q401 (6 pin)
/PSW Q402 (3 pin)
Checking the control signal output from the ASIC
Points to be checked
/FRST C110

TROUBLE SHOOTING

When an abnormal
value is confirmed.
Normal voltage
3.3V
1.5V
3.3V
3.1V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage (3.3V)
18.432MHz
18.432MHz
32.768kHz
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.3V
3.3V
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.3V
When a normal
value is confirmed.
NX-300(G)
Checking for an abnormal point
33M has an abnormal voltage.
[ASIC]
Remove L714 to check the voltage of the 33M.
If the voltage becomes normal, the ASIC is broken.
[DSP]
Remove L712 to check the voltage of the 33M.
If the voltage becomes normal, the DSP is broken.
[FLASH]
Remove L717 to check the voltage of the 33M.
If the voltage becomes normal, the FLASH is broken.
15M has an abnormal voltage.
[ASIC]
Remove L715 to check the voltage of the 15M.
If the voltage becomes normal, the ASIC is broken.
[DSP]
Remove L711 to check the voltage of the 15M.
If the voltage becomes normal, the DSP is broken.
33A has an abnormal voltage.
[ASIC]
Remove L716 to check the voltage of the 33A.
If the voltage becomes normal, the ASIC is broken.
31BU has an abnormal voltage.
[SRAM]
Remove L710 to check the voltage of the 31BU.
If the voltage becomes normal, the SRAM 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 ASIC is broken.
If the /FRST repeats 3.3V and 0V at intervals,
The ASIC, FLASH and SRAM may be broken.
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