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Customer Care Europe, Middle East & Africa
SCCE Training Group
CHAPTER 12: NO SERVICE
The first you should do if this fault occurs is to calibrate RX/TX-values of the phone. If only TX-power is too low or not measurable
continue with the chapter below. If only RX-calibration is impossible continue with the corresponding chapter on page 39.
If both TX-power and RX-calibration do not work, check spectrum charts on page 38 for possible failure reasons.
NO TX
Flowchart 12-1
GSM 1800
OK
Check
1747.8 MHz
at L512
OK
Check
1747.8 MHz
at C566
OK
Check
1747.8 MHz at
N502, pin3
OK
Check
1747.8 MHz
at J502
© NMP 2002
No or too low
TX-power GSM 900
Use WinTesla to set phone
into TX mode (GSM 900
Ch.38, GSM 1800 Ch.700).
Check
26 MHz REFCLK at
C546, -10dBm,
frequency deviation
<100 Hz
OK
Check
TX/IQ signals at
R541/548
OK
Check signals for HAGAR N500:
VTCXO 2.7 VDC at C506/518; VSYNTE 2.7 VDC at C501/504;
nOK
VRXRF 2.8 VDC at C500/503; VCHP 4.7 VDC at C505;
VREF_2 1.35 VDC at C535/536; RXREF 1.2 VDC at C529,
SDATA at R300; SCLK/SENA at R301; HAGARRESET at C540
Check SHF-oscillator at T502 pin3/4 (GSM 900 TX Ch.38: 3590.4
MHz, GSM1800 TX Ch.700: 3495.6 MHz)
If signals are ok but no TX-signal is measurable at L512/514,
change HAGAR N500
Check/change
nOK
T503
Check R542,
nOK
change N502
Ckeck L515/Z502 in
nOK
& out, also check
C593
CONFIDENTIAL
NHM—2/5/6
3410
Date 20.11.2002
Check Vtcxo 2.6 VDC at C543/544,
also check AFC-voltage at C552,
nOK
normally 1.2 VDC.
Change G502 if frequency deviation
is >100 Hz.
Check VBB 2.8 VDC at C119, check
VCOBBA 2.8 VDC at C116/117,
nOK
check VREF 1.5 VDC at C109,
check COBBACLK at J317,
if values OK, change COBBA N100
GSM 900
nOK
897.6 MHz
Check/change
nOK
897.6 MHz
T504/Z503/V601
Check C600, R550
nOK
897.6 MHz at
or change N502
N502, pin6
nOK
897.6 MHz
Checked by:
Customer Care E&A
Repairhints
Version 4.0 Approved
OK
Check
at L514
OK
Check
at C605
OK
Check
OK
Check
at J502
Approved by:
SCCE Training Group
33 (44)
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