Инструкции По Обслуживанию для Nokia 6620

Issue 2 10/2004

COMPANY CONFIDENTIAL

3

Copyright © 2004 Nokia. All Rights Reserved.

NHL-12

7 - RF Description & Troubleshooting

Nokia Customer Care

RF key component placement ...........................................................................  4
RF measurement points.....................................................................................  5

RF frequency plan..............................................................................................  8
RF power supply configuration ........................................................................  10

Receiver ...........................................................................................................  12
Rx front-end .....................................................................................................  12
General instructions for Rx troubleshooting .....................................................  14
Troubleshooting charts for receiver .................................................................  15

Troubleshooting diagram for GSM850 receiver  ............................................. 15
Troubleshooting diagram for GSM1900 receiver  ........................................... 17

Transmitter characteristics ...............................................................................  21
Power amplifier ................................................................................................  21
RF ASIC Helgo ................................................................................................  22
AFC function ....................................................................................................  22
General instructions for Tx troubleshooting .....................................................  23

Transmitter troubleshooting diagram  ............................................................. 24
Pictures of transmitter signals ........................................................................ 27

Frequency synthesizers ...................................................................................  37
General instructions for synthesizer troubleshooting .......................................  40