Advertisement
Customer Care Europe, Middle East & Africa
SCCE Training Group
In case the signal shown in figure 3-2 is not measurable, check voltages at reference oscillator G502:
Check VCC 2.6 VDC at G502 pin 2 and check control voltage (AFC) at pin 1 which normally is 1.2 VDC.
Note that control voltage may vary between 0.1 VDC and 2.3 VDC. Even without control voltage the oscillator
must be able to work on a frequency around 26 MHz as shown in the Figure 3-3.
If this is not the case you have to change G502.
26 MHz reference clock at the output
of G502: Amplitude is around –10 dBm.
If 26 MHz clock at G502 "out" is ok but no signal is measurable at C303, check 13 MHz system clock at C559:
Amplitude of 13 MHz system clock at
C559 is around –18 dBm.
If the signal shown above is not measurable, check VTCXO 2.7 VDC at C506/518. If both VTCXO and 26 MHz
reference clock are ok but 13 MHz system clock at C559 is not measurable, you have to change Hagar N500.
Remember to realign RX/TX-values after changing Hagar N500!
In case that 13 MHz system clock at C559 is ok but signal is not measurable at C303, check function of V502:
Check if voltage at base is 0.6 VDC and voltage at collector is 1.15 VDC. Amplitude of 13 MHz system clock
at base should be –25 dBm while amplitude at collector should be –8 dBm. Change V502 if necessary.
If 13 MHz system clock at C303 is ok check if PURX at R308 rises to 2.8 VDC after pressing the power switch.
If PURX-line keeps low, check line for shorts to ground. Resistance normally is around 5 M? .
In case that resistance is ok you have to change CCONT N201. Remember to run energy management
calibration after changing CCONT!
If also PURX is ok, try to flash the phone. In case of any failure message appearing while running SW-update, remember the
failure message and continue with chapter "Flash update not possible".
© NMP 2002
Figure 3-3
Figure 3-4
CONFIDENTIAL
NHM—2/5/6
3410
Date 20.11.2002
Checked by:
Customer Care E&A
19 (44)
Repairhints
Version 4.0 Approved
Approved by:
SCCE Training Group
Advertisement
