RF Troubleshooting Instructions
CCS Technical Documentation
Page 58
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Nokia Corporation
Issue 1 10/02
RF Troubleshooting
Phone settings for TX1900 Troubleshooting
TX – Burst mode
Channel 661
PCL10
No TX GSM1900
1 Check 26 MHz VCTCXO at TP20 (Test Point 20). Frequency deviation should be
<100 Hz). Check also TP3: Voltage should be 2.8VDC.
2 Check TX IQ signals at TP21. If not OK, change UEM.
3 Check 1880 MHz Ch661 at TP22. If OK, continue in step 8.
4 Check supply voltages for Hagar at TP4, TP5, TP6, TP8: 2.8 VDC; TP10 1.35 VDC
and TP1 4.8VDC. If voltages are not OK, change UEM.
5 . Check SDATA at TP51, SCLK TP53, SLE TP52.
6 Check TXC at TP23
7 Check frequency of VCO in TP40 (3760 MHz/ ch 661, TX mode). If not OK, check
TP7 2.8 VDC and TP41 ~2.8VDC. If TP41 is 4.8 VDC, the VCO doesn't probably
work. If all Hagar input signals are OK, probably HAGAR is broken -> Change
Hagar N600.
8 Check 1880 MHZ at TP25. If not OK, check Vbatt at TP9 3.9 VDC. Also check TP26.
If TP9 and TP26 are OK, PA is probably broken -> Change PA N700.
9 Check 1880 MHz at TP30. If not OK, check TP28. Also check TP 29 squarevawe 2.8
Vpp at burst mode. If TP28 and TP29 are OK, change Z500 (antenna switch)