User Guide

Nokia Customer Care Troubleshooting
Company Confidential RH-21
Issue 2 07/2004  2004 Nokia Corporation. Page 5
Troubleshooting
The first thing to do when a problem is encountered is to carry out a thorough visual
check of the module. Make sure that:
• there are no mechanical damages
• the solder joints are OK
Note: Before changing anything, ALL SUPPLY VOLTAGES AND THE SYSTEM CLOCK / SLEEP
CLOCK should be checked.
Baseband Troubleshooting
General testing information
There are three different modes for testing and/or repairing the phone. The mode can be
selected with suitable resistors connected to BSI- and BTEMP- lines as illustrated in the
following table:
If the corresponding resistors are connected, the MCU software automatically enters into
the local or test mode when the supply voltage is connected to the phone.
The power can be switched on by:
1 Pressing the power key.
2 Connecting the local/test mode resistors to the BSI/BTEMP lines and connecting
the battery voltage to the phone.
3 Connecting a charger.
4 Using the phone’s internal functions (real-time clock alarm).
In the local and test mode, the baseband can be controlled through MBUS or FBUS (FBUS
is recommended) connections using Phoenix service software.
Table 1: Phone operating mode
Mode BSI- resistor
BTEMP
resistor
Remarks
Nor-
mal
68k 75k
Local 560_(<1k_) Whatever
Test > 1k 560_(<1k_) Recommended for baseband testing. Same as
local mode, but making a phone call is possi-
ble.