User Guide

Nokia Customer Care

Appendix A: RF Troubleshooting

A-104

Company Confidential

4.2.4.3.4 Replace Hinku (N7500)

4.2.4.4 VXO-voltage ok? (=Vdig).

• Measurement can be done with an oscilloscope and a probe

• Connect the probe to C7560 (or C7526, C7513) Notice: C7526 is a non-assembled component so the

probe should be connected to the pad that can still be found from the PWB.

• VXO-voltage should be about 2.5 V

4.2.4.4.1 C7560, C7513, C7526 and C2214 ok?

• Check that components are in place and solder joints are ok

• Notice: C7526 is a non-assembled component so the probe should be connected to the pad that

can still be found from the PWB.

• Disconnect the power supply from the phone and use an ohmmeter to find out if the VXO-line is

short-circuited to the ground. If short-circuit is found replace C7560, C7513, C7526 and C2214. If

replacing does not help then go to the next steps.

4.2.4.4.2 Replace Retu

4.2.4.4.3 Replace Hinku (N7500) or Vinku (N7501) or VCTCXO (G7501) or all three components

4.2.4.5 VCP1-voltage ok?

• WCDMA receiver has to be active before VCP1 voltage can be measured. Procedure is explained in

section “Receiver troubleshooting”.

• Measurement can be done with an oscilloscope and a probe.

• Connect the probe to C7507.

• VCP1 voltage should be about 4.75 V.

4.2.4.5.1 C7507 and C2222 ok?

• 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

C7507 and C2222 are not short-circuited. If short-circuit is found replace faulty capacitor. If this

does not help go to the next steps.

4.2.4.5.2 Retu ok?

4.2.4.5.3 Hinku (N7500) ok?

4.2.4.6 Is there RF power in the RX VCO output at all?

• WCDMA receiver has to be active before RX VCO’s output frequency and output level can be

measured. Procedure is explained in section “Receiver troubleshooting”.