No Network Or No Call - Nokia RM-4 Troubleshooting Instructions

CCS Technical Documentation

No network or no call

If the phone doesn't register to the network, the fault can be in either BB or RF. Only few signals
can be tested since several signals is 'buried' in one or more of the inner layers of the PWB.
First of all check that it's not a SIM LOCK causing the error by using a Test-SIM card and con-
nect the phone to a tester.
or phone cannot make a call
12
Phone do not register to
network
C222, C223, C224, C225,
C226, C227
Voltage = ~2,78VDC
All during GSM frame-
call mode.
Use TXP on C646 as trigger
Yes
C230, C231
Voltage = ~1,35VDC
All during GSM frame (call mode)
Use TXP on C646 as trigger
Yes
J421, J422, J423
Check RF serial bus during
GSM-frame :
Logic HIGH = 1,8VDC
Logic LOW = 0VDC
RFBUSCLK (J421),
RFBUSDA (J422),
RFBUSEN1X (J423)
Yes
R601, R603
Check analog signals during
GSM-frame (RX slot):
RXIP/N (R601) = 0-1,45VDC
RXQP/N (R603) = 0-1,45VDC
Yes
R610, R611
Check analog signals during
GSM-frame (TX slot):
TXIP/N (R610) = 1-1,75VDC
TXQP/N (R611) = 1-1,75VDC
Yes
Check RF
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Copyright © 2003 Nokia. All Rights Reserved.
Troubleshooting Instructions
Check :
C222,C223, C224, C225,
No
C226, C227, PWB.
Else defective D200 or D400*
Check :
C230, C231, PWB.
No
Else defective
D200* or D400*
Check :
PWB.
No
Else defective D200*
or D400*
Check :
PWB.
No
Else defective D200*
or D400*
Check :
R610, R611,PWB.
No
Else defective D200*
or D400*
RM-4/RM-5
ISSUE 1 02/2004