Wcdma Modulation Spectrum And Aclr Ok; Does N7504 Give Correct Voltage Level (Vcc11) To The Wcdma Pa (N7503) - Nokia 6680 RM-36 Service Manual

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• 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 dBm).
NOTE: Perform WCDMA transmitter tests with > 0 dBm power only in RF shielded environment.
4.3.1.1 L7515, C7589 and C7580 in place and 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 L7515 is
conducting DC.
• Use an ohmmeter also to check that capacitors are not short-circuited. If short-circuit is found
replace capacitors mentioned above.
4.3.1.2 Does SMPS N7504 get operating voltage Vdd (=VBAT_PA)?
• WCDMA transmitter has to be active before measurements. Procedure is explained in section
A-108
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Appendix A: RF Troubleshooting