User Guide

Nokia Customer Care

RM-1

RF Troubleshooting

Company Confidential

7A - 25

Issue 1

3.1.1.1.3 Vinku (N7501) regulator voltages VREG1, VREG2 ok?

• GSM transmitter has to be active before VREG1 and VREG2 voltages can be measured.

Procedure is explained in chapter “General instructions for TX troubleshooting.”

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

• VREG1: Connect the probe to C7543

• VREG2: Connect the probe to C7548 (or C7547)

• VREG1 and VREG2 voltage levels should be 2.65 – 2.86 V. Typical value is 2.7 V.

3.1.1.1.3.1 Vinku (N7501) RB_EXT voltage ok?

• GSM transmitter has to be active before Vinku’s RB_EXT voltage can be measured.

Procedure is explained in chapter “General instructions for TX troubleshooting”.

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

• Connect the probe to R7521.

• RB_EXT voltage should be 1.325 – 1.375 V.

3.1.1.1.3.1.1 VREFRF01-voltage ok?

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

• Connect the probe to R7503.

• VREFRF01 voltage should be 1.325 – 1.375 V. Typical value is 1.35 V.

3.1.1.1.3.1.1.1 Desolder R7503. Is VREFRF01 voltage still wrong?

• Remember to solder a new component to R7503 pads after the measurement.

3.1.1.1.3.1.2 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 R7521 and R7504 resistance

values with an ohmmeter.

3.1.1.1.3.1.3 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.