User Guide

Appendix A: RF Troubleshooting
Nokia Customer Care
Company Confidential
Copyright © 2005 Nokia. All rights reserved
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4.2.4.11.2.3 Replace Retu
4.2.4.11.3 Replace VCTCXO G7501
4.2.5 Does RAP3G ASIC get ok VREFCM-signal from Hinku (N7500)? Signal level ok?
• Measurement can be done with an oscilloscope and a probe.
• Connect the probe to J7516.
• VREFCM voltage should be about 780 mV (continuous voltage).
4.2.5.1 Hinku (N7500) RB_EXT voltage ok?
• See section
"Hinku (N7501) RB_EXT voltage ok?"
4.2.5.2 Replace Hinku (N7500)
• Also RAP3G can be faulty but it’s not possible to replace this component
4.2.6 RAP3G faulty?
• Not possible to replace!
4.3 WCDMA modulation spectrum and ACLR ok?
• WCDMA transmitter has to be active before measurements. Procedure is explained in section
“Transmitter troubleshooting”.
• Measurement can be done with a WCDMA transmitter tester or other WCDMA communication
tester. Settings have to be done according to the 3GPP specifications. Modulation spectrum and
ACLR measurements are possible to perform also with a spectrum analyser, but in this case
measurement settings have to be done manually according to the 3GPP specifications.
• Attach the phone to the product specific test jig and a spectrum analyser or other
RF-measurement device to the RF-coupler. Coupler attenuation should be also taken into account
during measurements.
• If modulation spectrum is not as expected separate the phone into parts and place to the module
jig (Notice that there are three antenna connectors in the module jig, one for GSM, one for WCDMA
and one for Bluetooth. Make sure that all connections are made to the correct RF-connector).
4.3.1 Does N7504 give correct voltage level (Vcc11) to the WCDMA PA (N7503)?
• WCDMA transmitter has to be active before measurements. Procedure is explained in section
“Transmitter troubleshooting”.
• Set TX power level to -40 dBm (Set start level to “-40.0” in Phoenix)
• Measurements can be done with an oscilloscope and a probe.
• Connect the probe to C7580.
• Vcc11 voltage level should be about 1.5 V. The same voltage level should be measured also with all
power levels smaller than about 10 dBm. Vcc11 is about 3.3 V with the highest power (21