Troubleshooting; Baseband Troubleshooting; General Testing Information - Nokia RH-21 Series Troubleshooting Manual

CCS Technical Documentation

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:
Mode BSI- resistor
Normal 68k
Local 560_(<1k_)
Test > 1k
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.
Troubleshooting
Note: Most of the baseband repair actions require removing the baseband shield. The shield must not
be removed unless separately authorized by the program.
Issue 1 05/2003 Confidential
Table 1: Phone operating mode
BTEMP
Remarks
resistor
75k
Whatever
560_(<1k_) Recommended for baseband testing. Same as local
mode, but making a phone call is possible.
Nokia Corporation
RH-21
Troubleshooting
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