CONFIDENTIAL
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Customer Care Europe, Middel East & Africa NHM-8 / RH-9 Repairhints
SCCE Training Group Version 2.0 Approved
2003 Nokia Mobile Phones
Date 10-03-2003
© NMP 2003
Checked by: SCCE
Approved by: Training Group
Poweramplifier N700
In case that power amplifier N700 seems to be responsible for the TX-fault, first check the following voltages and signals that are
necessary for a proper working amplifier before exchanging N700.
Set phone with Phoenix to local mode and activate TX-burstmode Ch.37 (Ch.700 for GSM1800).
- Check VBATT 4VDC at both sides of L703
- Check VPCTRL_G 0.8Vpp – 1.4Vpp dependent on TX powerlevel at R713 (GSM 1800: VPCTRL_P at R708)
Figure 15: VPCTRL_G at R713
- Check VTX_B_G 2.7Vpp at R717 (GSM 1800: VTX_B_P at R719)
Figure 16: VTX_B_G at R717
- Check VTXLO_G 2.7Vpp squarewave in GSM 900 TX powerlevel 5 & 6 at R716. If TX powerlevel is 7 or lower signal at R716 is
2.7VDC. (For GSM 1800 switching between high/low mode is not available)
Figure 17: VTXLO_G at R716
If the signal at the amplifier´s input at R714 (GSM 1800: R711) and the above mentioned signals are ok but still there is no or too
low TX power at the amplifier´s output, it is necessary to exchange N700. Remember to perform RF-calibrations after having
exchanged the power amplifier.
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