NXR-901
74
■
Traceability Procedure of IC17 (Flash Memory of RF control MPU)
Confi rmation of Power Source Voltage
Test
Point Normal
Output
Voltage
IC329 (pin 5) 3.3VDC
Correct
condition
Confi rmation of Reset control
Test
Point Normal
Control
Voltage
R137 3.3VDC
(either end of R137 is OK)
Correct
condition
Parts other than IC17 are malfunctioning.
■
Traceability Procedure of IC325 (The Modem control MPU)
Confi rmation of Power Source Voltage
Test
point Normal
output
voltage
IC15
(pin
3) 3.3VDC
Correct
condition
Confi rmation of Clock frequency
Test
Point Proper
Frequency
R566 14.7456MHz
(either end of R566 is OK)
Correct
condition
Confi rmation of Reset control
Test
Point Normal
Control
Voltage
IC303
(pin
1) 3.3VDC
Correct
condition
Parts other than IC325 are malfunctioning.
Confi rmation of IC329 (pin 5) output.
Remove R159 and if 3.3VDC, one of IC17, IC34,
IC28, IC32, IC33, or IC40 is malfunctioning.
Confi rmation of the clock and reset control of IC34
Confi rmation of clock frequency:
If 14.7456MHz cannot be confi rmed at the edges of
R195:
X1 is malfunctioning or the circuit around X1 is mal-
functioning.
If the clock oscillation amplitude is weak at the edg-
es of R195, the drive circuit in IC34 is malfunction-
ing.
Reset control confi rmation
Remove R232 and then confi rm the voltage of the
pad on the opposite side of IC34.
If 3.3VDC, IC34 is malfunctioning.
If both Clock and Reset control are working prop-
erly, one of IC17, IC28, IC32, IC33, or IC40 is mal-
functioning.
Abnormal
condition
Abnormal
condition
Confi rmation of IC15 (pin 3) output
Remove R484. If 3.3VDC, IC325 is malfunctioning.
If the oscillation of 14.7456MHz cannot be con-
fi rmed:
X301 is malfunctioning or the circuit around X301 is
malfunctioning.
The clock oscillation amplitude is weak:
The drive circuit in IC325 is malfunctioning.
Remove R559 and confi rm the voltage on the pad
at the reverse side of IC325:
If 3.3VDC, IC325 is malfunctioning.
Abnormal
condition
Abnormal
condition
Abnormal
condition
TROUBLE SHOOTING
Summary of Contents for NEXEDGE NXR-901
Page 154: ...1 E CN300 RX_IF_VN ...