User Guide

CC Technical Documentation Troubleshooting - BB
NPM-10 (3595)
Issue 2 03/2004 ©2004 Nokia Corporation Confidential Page 9
Phone Does Not Register Onto the Network, or the Phone Cannot Make a Call
If the phone does not register to the network, the fault can be in either BB or RF. Only a
few signals can be tested because several signals are buried in one or more of the inner
layers of the PWB. First, check that the SIM LOCK is not causing the error by using a
Test-SIM card and connecting the phone to a tester.
Figure 6: Phone does not register to network or phone cannot make a call
Phone does not register to
network or phone cannot
make a call
C222, C223, C224, C225, C226, C227
Voltage = ~2.78 VDC all during GSM frame (call
mode). Use TXP on C646 as trigger.
Yes
CHECK:
C222, C223, C224, C225, C226,
C227, PWB. Else defective D200
or D400*
No
No
No
CHECK:
C230, C231, PWB. Else defective
D200* or D400*
CHECK:
PWB. Else defective D200* or
D400*
CHECK RF
No
C230, C231
Voltage = ~1.35 VDC all during
GSM-frame (call mode).
Use TXP on C646 as trigger.
J608, J609, J610
Check RF serial bus during GSM frame:
Logic HIGH = 1.8 VDC
Logic LOW = 0 VDC
RFBUSCLK (J608), RFBUSDA (J609),
RFBUSEN1X (J610)
R601, R603
Check analog signals during GSM-frame (RX slot):
RXIP/N (R601) = 0-1.45 VDC
RXQP/N (R603) = 0-1.45 VDC
R610, R611
Check analog signals during GSM-frame (TX slot):
TXIP/N (R610) = 1-1.75 VDC
TXQP/N (R611) = 1-1.75 VDC
Yes
Yes
Yes
Yes
CHECK:
PWB. Else defective D200* or
D400*
CHECK:
R610, R611, PWB. Else defective
D200* or D400*
No