Nokia 616 - Fault Finding Chart for EGSM900 Transmitter

Nokia Customer Care TF4 Technical Information
Company Confidential TFE-4/RV-1
Issue 2.0 Mar/2005 Copyright © 2005 Nokia Corporation. Page 8b-57
Company Confidential
Fault finding chart for EGSM900 transmitter
The TXP signal is intended to be used as trigger, a test point is provided.
Use Phoenix to select
TX_Data Type: "1" or "0"
TX Power Level: 10
Yes
n
Oscilloscope
R612 VREF01 Vdc = 1.35 Volt Check
C627 VR2 Vdc = 2.78 Volt No Base Band
C717 TXP V = 1.8 Volt
C623 VR5 Vdc = 2.78 Volt
C605 VR3 Vdc = 2.78 Volt
Yes
n
Oscilloscope
C715 TXIOUTP
67kHz
Vac = 0.4 Vpp, Vdc = 1.1 V
No
Check
C715 TXIOUTN
67kHz
Vac = 0.4 Vpp, Vdc = 1.1 V
Base Band
C716 TXQOUTP
67kHz
Vac = 0.4 Vpp, Vdc = 1.1 V
C716 TXQOUTN
67kHz
Vac = 0.4 Vpp, Vdc = 1.1 V
Yes
n
Oscilloscope
R823 VTXB_900 Vdc = 2.78 Volt No Check:
Mjoelner Serial
Interface
Mjoelner
C702 CONT1 Vdc = 0 Volt
C701 CONT2 Vdc = 0 Volt
C703 CONT3 Vdc = 2.78 Volt
C803 VBD Vdc = 2.78 Volt
Yes
n
Spectrum analyzer No Check
Z701 out, R806 in TX_900 P>= -3 dBm, 897,4 MHz EGSM TX SAW Filter
Compare with good sample Mjoelner
Yes
n
Synthesizer
Use Phoenix to select
TX_Data Type: Random
TX Power Level: 10
Yes
n
Spectrum analyzer Check PA N801
L801 B1_in (PA N801
Pout_GSM)
No
Check Power Loop
L801,V801
Power = +25 dBm, 897,4 MHz Check TXC
Yes
n
Spectrum analyzer Check
RF-connector No Directional Coupler (L801)
Pout =+23 dBm, 897,4 MHz Antenna Switch (Z601)
Yes
n
EGSM TX
OK