Nokia RM-42 Service Manual

Also see for RM-42: Service manual

Contents

Appendix A: RF Troubleshooting Nokia Customer CareCompany ConfidentialCopyright © 2005 Nokia. All rights reservedA-53• Check that components are in place and solder joints are ok• Disconnect the power supply from the phone and use an ohmmeter to check that capacitors arenot short-circuited. If short-circuit is found replace capacitors mentioned above. If this does nothelp go to the next step.3.2.2.3.1.1.1.2 Replace Vinku (N7501) or Hinku (N7500) or both3.2.2.3.1.1.2 Retu ok?3.2.2.3.1.2 R7521 and R7504 in place and working correctly?• Check that components are in place and solder joints are ok• Disconnect the power supply from the phone and check R521 and R504 resistance values with anohmmeter.3.2.2.3.1.3 VB_EXT voltage ok?• Measurement can be done with an oscilloscope and a probe.• Connect the probe to C7518.• VB_EXT voltage should be 1.325 – 1.375 V. Typical value is 1.35 V.3.2.2.3.1.3.1 R7503 in place and working correctly?• Check that the component is in place and solder joints are ok• Disconnect the power supply from the phone and check R7503 resistance value with an ohmmeter3.2.2.3.1.3.2 Capacitors C7518, C7520 and C7570 working correctly?• Check that components are in place and solder joints are ok• Disconnect the power supply from the phone and use an ohmmeter to check that capacitors arenot short-circuited. If short-circuit is found replace capacitors mentioned above. If this does nothelp go to the next step.3.2.2.3.1.3.3 Replace Hinku (N7500) or Vinku (N7501) or both3.2.2.3.1.4 Replace Hinku (N7500)3.2.2.3.2 Are capacitors in Hinku (N7500) regulator lines working correctly?C7504, C7515, C7509, C7508, C7596, C7598 and C7505• Check that components are in place and solder joints are ok• Disconnect the power supply from the phone and use an ohmmeter to check that capacitors arenot short-circuited. If short-circuit is found replace capacitors mentioned above. If this does nothelp go to the next step.3.2.2.3.3 RX VCO G7500 ok?