The Phone Do Not Register To The Network, Or The Phone Cannot Make A Call - Nokia RH-18 Troubleshooting Instructions

RH-18/36/38

The phone do not register to the network, or the phone cannot make a 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 'burried' in one or more of the inner layers of
the PWB.
First of all check that SIM LOCK is not causing the error by using a Test-SIM card and
connect the phone to a tester.
Phone do not register to
or phone cannot make a call
C222, C223, C224, C225,
Use TXP on C646 as trigger
All during GSM frame (call mode)
Use TXP on C646 as trigger
Check RF serial bus during
Check analog signals during
RXIP/N (R601) = 0-1,45VDC
RXQP/N (R603) = 0-1,45VDC
Check analog signals during
TXIP/N (R610) = 1-1,75VDC
TXQP/N (R611) = 1-1,75VDC
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network
C226, C227
Voltage = ~2,78VDC
All during GSM frame-
call mode.
Yes
C230, C231
Voltage = ~1,35VDC
Yes
J421, J422, J423
GSM-frame :
Logic HIGH = 1,8VDC
Logic LOW = 0VDC
RFBUSCLK (J421),
RFBUSDA (J422),
RFBUSEN1X (J423)
Yes
R601, R603
GSM-frame (RX slot):
Yes
R610, R611
GSM-frame (TX slot):
Yes
Check RF
Figure 5: No call troubleshooting
Nokia Corporation.
CCS Technical Documentation
Check :
C222,C223, C224, C225,
No
C226, C227, PW B.
Else defective D200 or D400*
Check :
C230, C231, PW B.
No
Else defective
D200* or D400*
Check :
PW B.
No
Else defective D200*
or D400*
Check :
PW B.
No
Else defective D200*
or D400*
Check :
R610, R611,PW B.
No
Else defective D200*
or D400*
Issue 1 10/03