User Guide

PAMS Technical Documentation 6 - Troubleshooting
NPE-4
Original ãNokia Corporation. Page 6-39
Fault finding chart for EGSM transmitter
Oscilloscope
R726 VREFRF01 Vdc = 1.5 Volt Check
C656 VR2 Vdc = 2.7 Volt
No BaseBand
C760 TXP Vdc > 2.5 Volt
C601 VR4 Vdc = 2.7 Volt
Yes
Oscilloscope
R764 TXIOUTP 67kHz
Vac = 0.4 Vpp, Vdc = 0.8 V
No
Check
R764 TXIOUTN 67kHz
Vac = 0.4 Vpp, Vdc = 0.8 V
BaseBand
R766 TXQOUTP 67kHz
Vac = 0.4 Vpp, Vdc = 0.8 V
R766 TXQOUTN 67kHz
Vac = 0.4 Vpp, Vdc = 0.8 V
Yes
Oscilloscope
C856
VTXB_900 Vdc > 2.0 Volt No Check:
C866 VTXB_1800 Vdc < 0.3 Volt
Hagar Serial Interface
C808 VANT1 Vdc < 0.3 Volt
Hagar
C809 VANT2 Vdc > 2.0 Volt
C830 VBD Vdc > 2.0 Volt
Yes
Spectrum analyser No Check
Z650 out, R858 in TX_900 Power > -3 dBm, 897,4 MHz
EGSM TX SAW Filter
Hagar
Yes Synthesiser
Use Wintesla to select
TX_Data Type: Random
TX Power Level: 10
Yes
Spectrum analyser Check PA N840
L836 EGSM in
(PA N840 EGSM out)
No
Check Power Loop
L836,V830
Power = +25 dBm, 897,4 MHz Check TXC
Yes
Spectrum analyser Check
RF-connector No Directional Coupler (L836)
Pout = +23 dBm, 897,4 MHz RX/TX Switch (Z802)
Yes
EGSM TX
OK