Chapter 8: No Service - Nokia 3510 Repair Manual

Customer Care Europe, Middel East & Africa
SCCE Training Group
 2003 Nokia Mobile Phones

CHAPTER 8: No Service

In case that it is not possible to establish a call with your phone, the first thing to do is to perform all RF-calibrations to find out
more about the fault. If for example TX-power is not measurable or too low, check transmitters signal path beginning with e.g.
TXIQ signals at R610/611. If the receiver does not work properly, check receivers signal path beginning e.g. with the incoming RF-
signal at diplexer Z700. If both RX and TX do not work check parts which are needed for both signal pathes (e.g. supply voltages,
oscillators B600, G600 or Mjoelner N600).
No or too low TX-power
Mjoelner N600
If you suppose Mjoelner N600 to be responsible for the TX-fault, first check the following signals before exchanging N600.
Set phone with Phoenix to local mode and activate TX-burstmode Ch.37 (Ch.700 for GSM1800).
Check supply voltages VR1A 4.7VDC at both sides of R603, VR2 2.8VDC at C612, VR3 2.8VDC at C618, VR5 2.8VDC at C614,
-
VR6 2.8VDC at C610, VR7 2.8VDC at C624, VIO 1.8VDC at C621 and VREF01 1.35VDC at C626.
- Check 26MHz reference clock at J425. Unfortunately it is not possible to check the signal of the SHF-oscillator directly, but
you can check the control voltage at C641: if this voltage is outside its normal range (1.2VDC up to 3.2VDC) this indicates
that the oscillator probably is faulty or the control loop is open. Further more check ResetX_Mjoelner at R604, which
normally is 1.8VDC.
Figure 8: 26MHz at J425
- Check with an oscilloscope TXC at R637 (0.7Vpp – 1.8Vpp depending on TX-powerlevel), TXP 1.8Vpp at C646 and TX/IQ-
signals at both sides of C627/628:
Figure 9: TXC at R637
- Check with an oscilloscope RFBusData at J610, RFBusClk at J608 and RFBusEnable at J609:
Figure 12: RFBusData at J610
If all these signals are ok but no TX-signal is measurable at L606 (L604 in GSM1800), Mjoelner N600 is faulty in all probability.
© NMP 2003
CONFIDENTIAL
NHM-8 / RH-9
Date 10-03-2003
Figure 10: TXP at C646
Figure 13: RFBusClock at J608
Checked by: SCCE
16 (18)
Repairhints
Version 2.0 Approved
Figure 11: TXIQ at R610/611
Figure 14: RFBusEnable at J609
Approved by: Training Group