User Guide

PAMS Technical Documentation 6 - Troubleshooting
NPE-4
Original ãNokia Corporation. Page 6-11
The phone doesn’t register to the network or phone doesn’t make a call
If the phone doesn't register to the network, the fault can be in either BB or RF. Due to
the highly module design of the BB area, very few signals can be measured.
SIM Failure
The hardware of the SIM interface from UEM (D200) to the SIM connector (X386) can be
tested without a SIM card. When the power is switched on the phone first check for a
1,8V SIM card and then a 3V SIM card. The phone will try this four times, whereafter it
will display "Insert SIM card".
Phone doesn't register to network
or phone doesn't make a call
C292 towards D200 (UEM) ~4.75 VDC
C294 towards R308 ~2.78 VDC
C295 towards UEM ~2.78 VDC
C296 towards V311 ~2.78 VDC
C297 towards UEM ~2.78 VDC
C298 towards R307 ~2.78 VDC
C299 towards V311 ~2.78 VDC
C288 towards R306 = 1.35 VDC
C289 towards UEM = 1.35 VDC
all during GSM frame. Use TXP on J760.
Yes
Check:
D200, D400,PWB
No
Check RF serial bus:
RFBUSCLK on J731/J735
RFBUSDA on J732/J76
RFBUSEN1X on J730/J734
Transitions "1" <-> "0",
1.8 VDC <-> 0 VDC during GSM frame
Yes
Check:
D400,PWB
No
Check analog signals during
GSM frame (Rx slot):
RXINP on C724 towards C716 = 0-1.45 VDC
RXQINP on C725 towards C716 = 0-1.45 VDC
Yes
Check:
D200,D400,PWB
No
Yes
Check analog common mode signals during
GSM frame (Tx slot):
TXIOUTP on R764 pin 1 towards R766 and
TXIOUTN on pin 3 = 1-1.75 VDC
TXQOUTP on R766 pin 1 towards R764and
PXQOUTN on pin 3 = 1-1.75 VDC
Check:
D200,D400,R764,
R766,PWB
No
Check RF
Yes