Nokia RH-27 Series User manual

CCS Technical Documentation
RH-27 Series Transceivers
Issue 1 11/2003 Confidential ©2003 Nokia Corporation
Troubleshooting - GPS

RH-27
Troubleshooting - GPS CCS Technical Documentation
Page 2 ©2003 Nokia Corporation Confidential Issue 1 11/2003
Contents Page No
Troubleshooting - Global Positioning System (GPS) Engine........................................ 3
GPS General Block Diagram .......................................................................................3
GPS RF Schematic ......................................................................................................3
GPS Testing .................................................................................................................4
GPS RF Probing Setup ................................................................................................7
GPS RF Probing Measurements................................................................................ 8

CCS Technical Documentation Troubleshooting - GPS
RH-27
Issue 1 11/2003 Confidential ©2003 Nokia Corporation Page 3
Troubleshooting - Global Positioning System (GPS) Engine
The RH-27 handset supports 800 Amps and 800 CDMA / 1900 CDMA + GPS with IS 2000
capability. The RH-27 engine supports CDMA and GPS functionality for Enhanced 911
(E911) services.
GPS circuitry utilizes RF signals from satellites stationed in geosynchronous orbit to
determine latitude and longitude of the handset. The GPS circuitry and the cellular
engine (CE) circuitry are completely separate in the handset. The GPS circuitry is located
almost exclusively on the secondary side of the PWB, underneath the display module.
GPS General Block Diagram
GPS RF Schematic
ADC
Synthesiser
TRF5101
LNA
FilterFilter
4
AGC
Amp
Xtal
16.368MHz
IF = 4.092MHz
Ref Clk
Rx Data
Out
GPS
Baseband
Cellular Baseband
GPS RF
R
F Input
Filter 1 (Z001)
Filter 2 (Z002)
GPS RF Chip (N001)
Circuits located on Bottom Layer Circuits located on Top Layer

RH-27
Troubleshooting - GPS CCS Technical Documentation
Page 4 ©2003 Nokia Corporation Confidential Issue 1 11/2003
GPS Testing
1 Set Local Mode.
2 Inject -110dBm tone @ 1575.52MHz at GPS connector (X001) with signal gener-
ator or call box.
3 Open “GPS Control” from the “BB/Hwd” drop-down menu.
Signal Generator
RF OUT
Signal Generator
RF OUT
4. Execute the GPS Quick Test.
5. Analyze Results: See next figures.

CCS Technical Documentation Troubleshooting - GPS
RH-27
Issue 1 11/2003 Confidential ©2003 Nokia Corporation Page 5
5a. Self-Test Failure:
• Repeat Steps 1-5 for first failure. If the test still fails, continue.
• Inspect all GPS circuit elements around D051.
• If pass visual inspection, then replace D051.
5b. Oscillator Failure:
• Inspect all GPS circuit elements around D051.
• If pass visual inspection, then replace B002.
5c. CW Test Failure:
• Check that signal generator is on and sourcing a signal to the GPS RF input port (X001).
• Inspect all GPS RF circuit elements.
• Inspect all GPS circuit elements around D051.
• If all visual inspection looks good, then replace GPS RF IC (N001).
Top Layer
D051
B002

RH-27
Troubleshooting - GPS CCS Technical Documentation
Page 6 ©2003 Nokia Corporation Confidential Issue 1 11/2003
INSPECT!

CCS Technical Documentation Troubleshooting - GPS
RH-27
Issue 1 11/2003 Confidential ©2003 Nokia Corporation Page 7
GPS RF Probing Setup
1 Turn on the GPS Receiver
2 Inject -25dBm tone @ 1575.52MHz at GPS Connector (X001) with signal gener-
ator or Call Box.
3 Continue to the GPS RF Probing Diagram diagram which follows, and measure
probe points with either a FET probe and a spectrum analyzer set at center fre-
quency 1575.25MHz, Span = 500kHz, or a voltmeter as specified.
Signal Generator
RF OUT
Signal Generator
RF OUT

RH-27
Troubleshooting - GPS CCS Technical Documentation
Page 8 ©2003 Nokia Corporation Confidential Issue 1 11/2003
GPS RF Probing Measurements
PT Description Value Instrument
LNA output 1575.25MHz @ -19.5dBm spectrum analyzer
2nd BPF output 1575.25MHz @ -21dBm spectrum analyzer
TXCO supply VRF_GPS 2.78V (DC) voltmeter
TXCO output freq 16.368MHz @ +6dBm spectrum analyzer
2
1
3
4
1
2
3
4