User Guide
Table Of Contents
- Amendment Record Sheet
- Copyright
- Warnings and cautions
- For your safety
- Care and maintenance
- ESD protection
- Battery information
- Company Policy
- Nokia 5000 Service Manual Structure
- 1 General Information
- 2 Service Devices and Service Concepts
- 3 Baseband Troubleshooting Instructions
- General baseband troubleshooting
- SIM related faults
- User interface
- Audio troubleshooting
- Audio troubleshooting using phoenix
- Check microphone using "Hp microphone in Ext speaker out" loop
- Check earpiece using "Ext microphone in Hp speaker out" loop
- Check IHF & ringing tone function using "Buzzer"
- Check vibra function using "Vibra control"
- Earpiece fault
- IHF/ringing tone fault
- Microphone fault
- Headset earpiece fault
- Headset microphone fault
- 4 RF Troubleshooting Instructions
- 5 Camera Module Troubleshooting
- 6 System Module
- Glossary
Figure 78 TXC signals at PCL15
Synthesizer troubleshooting
Introduction
26 MHz Reference Oscillator (VCXO)
There is only one PLL synthesizer generating Local Oscillator frequencies for both RX and TX in both bands
(PCN and EGSM). The VCO frequency is divided by 2 for PCN operation or by 4 for EGSM operation inside the
Mjoelner IC.
The 26MHz oscillator is located near the Mjoelner IC. (N7600). The coarse frequency for this oscillator is set
by an external crystal (B7600). The reference oscillator is used as a reference frequency for the PLL synthesizer
and as the system clock for the Baseband. The 26MHz signal is divided by 2 to achieve 13MHz inside the UPP
IC (D2800).
The 26MHz signal from the VCXO can be measured by probing R2900. The level at this point is approx.
770mVpp. Frequency of this oscillator is adjusted by changing the AFC-register inside the UEM IC. Example
Signal Measured at VCXO output (R2900).
RM-362; RM-363
RF Troubleshooting Instructions
Issue 1 COMPANY CONFIDENTIAL Page 4 –45
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