Kenwood NX-3720HG Service Manual page 154

*1
If 12M, 18M or 32M has still an abnormal voltage after the implementation of each procedure above,
54M(IC25),12M(IC24),18M(IC12),32M(IC20) or one of these peripheral circuit is broken.
54M(normally 5.4V at L13) has an abnormal voltage, check the MSP430(IC22) according to the following procedure.
Checking the operation of the MSP430
Check that the voltage of VIN of 54M(IC25 - 8pin)
is 13.6V.
Standard Voltage/Operating Voltage range
K Type 13.6V/13.6 15%
E type 13.2V/10.8V~15.6V.
Check that the signal BAT_CNT
of MSP430(IC22 - 7pin) outputs High(3.1V).
Check that the voltage of DVCC of MSP430(IC22 - 1pin)
is 3.1V.
Check that the analog voltage
of /BINT(IC22 - 5pin) is normal(typically 2.6V.
Operating voltage range is 1.6V~3.0V).
*2 Checking the operation of the MSP430 (/RST)
When the signal /RST(IC22 - 14pin) has an
abnormal output, check that the analog voltage of
/RST(IC22 - 6pin) is normal.(typically 2.7V.
Minimum detection voltage is 2.0V.).
Checking the operation of MSP430 (/BINT)
When the signal /BINT(IC22 - 13pin) has an abnormal
outputs, check that the signal /RST(IC22 - 14pin) has
correct output.
Checking the operation of MSP430 (/OVRB_OUT)
When the signal /OVRB_OUT has an abnormal outputs,
check that the /OVRB(IC22 - 2pin) is High(3.1V) in the
deck powered on.
1-154 (No.RA054<Rev.001>)
When VIN of 54M
is 0V.
When VIN of 54M is
out of operating
voltage range.
Pass
Pass
Fail
Fail
Pass
Pass
Fail
Pass
Fail
Pass
Fail
Pass
Check the voltage (13.6V[operating voltage range])
at both ends of F1(fuse). If F1 is broken, replace the
F1 with a new one. If F1 is not broken, 54M(IC25) or
its peripheral circuit is broken.
Set the supply voltage within the operating voltage
range. if set correctly, 54M(IC25) or its peripheral
circuit is broken.
54M(IC25) or its peripheral circuit is broken.
MSP430, 31BU, 50BU or one of these peripheral
circuit is broken.
MSP430 is broken.
Set the supply voltage within the operating voltage
range. If set correctly, MSP430 or its peripheral
circuit is broken.
MSP430 is broken.
MSP430, 54M(IC25) or its peripheral circuit of is
broken.
MSP430 or its peripheral circuit of is broken.
MSP430 or its peripheral circuit is broken.
MSP430 is broken.