Gps Troubleshooting; Gps Receiver - Nokia RH-3 Series Troubleshooting - Rf

RH-3
Troubleshooting - RF
Rx AGC vs RF Pin for CELL and PCS
Bands
Conn RF
Pin
-95
-96
-100
-105
-107
UNITS

GPS Troubleshooting

Measurements should be done using High-Frequency Probe with spectrum analyzer in
order to measure local and reference frequencies and RF-power levels in intermediate
stages of chain. Oscilloscope is used to measure DC-voltages and low frequency signals.
Digital multimeter is also useful measurement equipment in faultfinding. Also cellular
tester is needed in order to perform tests mentioned in this document.
External RF connector is implemented for improving reliability of the measurements and
should be used when reasonable.
GPS RF section is mainly build around of TRF5101 PG2.1 IC (N001). The GPS RF block has
a separate front end filter, inter stage filter, LNA, TCXO, and down converter circuitry.
In this RF troubleshooting document, tolerances are specified for critical GPS RF signals
and voltages.
Before changing a single ASIC or component, please check the following:
1 The soldering and alignment marks of the GPS ASICs
2 Supply voltages and control signals are OK
The RF ASIC module is static-discharge sensitive! So it is recommended to wear EDS-pro-
tected clothes and shoes and to use grounded soldering irons.
The shield lid must be always replaced with new one after it is opened. Check that there
are no short circuits on PWB caused by plate ends.

GPS Receiver

Receiver troubleshooting is divided into four sections:
Page 36
CELL PCS
RF AGC RF AGC
0.431 0.66
0.651 0.646
0.594 0.59
0.524 0.59
0.493 0.485
VDC VDC
Nokia Corporation
CCS Technical Documentation
Comments
Note the reduced delta because the LNA is
switched on
LNA switch hysteresis: -94 on the way down,
-89 on the way up
Confidential Issue 1 06/2003