Nokia RM-42 Service Manual

Also see for RM-42: Service manual

Contents

Nokia Customer Care Appendix A: RF TroubleshootingA-54Company ConfidentialCopyright © 2005 Nokia. All rights reserved3.2.2.3.4 Replace Hinku (N7500)3.2.2.4 VXO-voltage ok? (=Vdig).• Measurement can be done with an oscilloscope and a probe• Connect the probe to C7560 (or C7526, C7513)• VXO-voltage should be about 2.5 V3.2.2.4.1 C7560, C7513, C7526 and C2214 ok?• Check that components are in place and solder joints are ok• Disconnect the power supply from the phone and use an ohmmeter to find out if the VXO-line isshort-circuited to the ground. If short-circuit is found replace C7560, C7513, C7526 and C2214. Ifreplacing does not help then go to the next steps.3.2.2.4.2 Replace Retu3.2.2.4.3 Replace Hinku (N7500) or Vinku (N7501) or VCTCXO (G7501) or all three components3.2.2.5 VCP1-voltage ok?• GSM receiver has to be active before VCP1 voltage can be measured. Procedure is explained insection “GSM RX chain activation for manual measurements”.• Measurement can be done with an oscilloscope and a probe.• Connect the probe to C7507.• VCP1 voltage should be about 4.75 V.3.2.2.5.1 C7507 and C2222 working properly?• Check that the components are in place and solder joints are ok• Disconnect the power supply from the phone and use an ohmmeter to check that C507 and C2222are not short-circuited.3.2.2.5.2 Retu ok?3.2.2.5.3 Hinku (N7500) ok?3.2.2.6 VCTCXO frequency and output level correct?• Measurement can be done with an oscilloscope and a probe.• Connect the probe to C7529 (or C7582)• The frequency of the VCTCXO should be quite exactly 38.4 MHz and level about 0.5 - 0.9 Vpp.Example of the correct VCTCXO output signal is presented in figure 6.5.1 "VCTCXO Output (DC Offset1.24 V)".