Voxtel BD20 User manual

GSM PHONE
SERVICE MANUAL
MODEL : BD20
1st version
(2004, 01, 27)

Rev. 1.00

I
Table Of Contents
1. Introduction ........................................................................................................ 1-1
2. Specification ....................................................................................................... 2-1
2.1 HW Features ................................................................................................................................................ 2-1
2.2 SW Features ................................................................................................................................................. 2-2
3. Disassembly Instruction ................................................................................................................. 3-1
3.1 Before Disassembly .................................................................................................................................... 3-1
3.2 Main Frame .................................................................................................................................................. 3-2
3.3 Folder ............................................................................................................................................................ 3-3
4. Data Kit & Download Procedure................................................................................................. 4-1
4.1 Data Kit ......................................................................................................................................................... 4-1
4.1.1 Download Equipment ....................................................................................................................... 4-1
4.1.2 Download Procedure ......................................................................................................................... 4-1
5. Troubleshooting...................................................................................................................................... 5-1
5.1 Power-On Trouble ....................................................................................................................................... 5-1
5.2 MIC Trouble ................................................................................................................................................. 5-2
5.3 Receiver Trouble .......................................................................................................................................... 5-3
5.4 Melody Trouble ........................................................................................................................................... 5-4
5.5 LCD Trouble ................................................................................................................................................ 5-5
5.6 Charge Trouble ............................................................................................................................................ 5-6
5.7 Vibrator Trouble .......................................................................................................................................... 5-7
5.8 7-LED Trouble............................................................................................................................................... 5-8
5.9 Key Backlight Trouble ................................................................................................................................ 5-9
5.10 TX Power Trouble (E-GSM).................................................................................................................... 5-10
5.11 TX Power Trouble (DCS)......................................................................................................................... 5-12
5.12 Rx Sensitivity Trouble (E-GSM) ............................................................................................................ 5-14
5.13 Rx Sensitivity Trouble (DCS) ................................................................................................................. 5-16

II
Table of Contets
6. PCB Diagram ......................................................................................................................................... 6-1
6.1 Main PCB ...................................................................................................................................................... 6-1
7. Electrical Parts List ........................................................................................................................... 7-1
7.1 Main Parts List ............................................................................................................................................ 7-1
8. Exploded View and Parts List ..................................................................................................... 8-1
8.1 Exploded View ............................................................................................................................................ 8-1
8.2 Mechanical Parts List ................................................................................................................................. 8-2
9. Block Diagram ....................................................................................................................................... 9-1
9.1 BB Block Diagram ....................................................................................................................................... 9-1
9.2 RF Block Diagram ....................................................................................................................................... 9-2
9.3 Power Supply Block Diagram.....................................................................................................................9-3
10. Schematic Diagram ...................................................................................................................... 10-1
10.1 Key Pad .................................................................................................................................................... 10-1
10.2 Main Board .............................................................................................................................................. 10-2
10.2.1 Chipset ............................................................................................................................................. 10-2
10.2.2 Memory & Melody ......................................................................................................................... 10-3
10.2.3 Audio & SIM ................................................................................................................................... 10-4
10.2.4 Connector ........................................................................................................................................ 10-5
10. 3 RF Top Schematic ................................................................................................................................... 10-6
10.3.1 RF Pam ............................................................................................................................................. 10-6
10.3.2 RF Main IC ...................................................................................................................................... 10-7

1. Introduction
BD20 is a folder type mobile phone operated in the GSM Digital Cellular Mobile Radio System, which is the
Pan-European mobile cellular standard. BD20 has the operation band of GSM 900 and DCS 1800. GSM Phase-
II features are fully supported and parts of the GSM Phase II+ features are also supported. About the SIM
Toolkit, BD20 supports up to Class 3 including Class 1, 2. For speech communication, BD20 supports Full
Rate(FR), Enhanced Full Rate(EFR) and Half Rate(HR). For easy text, eZi Text is implemented.
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