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-1135. DOES THE PHONE HAVE A RELIABLE CONNECTION TO THE NETWORK (GSM)?This section refers to a situation when the phone registers to the GSM-network and is capable to make a call, butthe call is not reliable even if the GSM-network field strength is strong. The phone call is maybe disconnected orinterrupted.5.1 GSM receiver Bit Error Rate (BER) ok?• This test needs a GSM communication tester and if there is no that kind of tester availablecontinue troubleshooting in section 3.2 “Does the phone give realistic RSSI-values?”.• Attach the phone to the product specific test jig and a GSM communication tester to theRF-coupler. Coupler attenuation should be also taken into account during measurements. Thismeasurement should be done in an RF shielded box.• Close the shield box hatch.• Make a GSM call against the tester• Settings to the tester have to be done according to the 3GPP specifications:- Set base station downlink power to -102 dBm• Bit Error Rate should be less than 2 %5.1.1 Does the phone give realistic RSSI-values?• See section 3.2. “Does the phone give realistic RSSI-values?”5.1.2 Hinku (N7500) or RAP3G (D2800) faulty?• RAP3G is not possible to replace5.2 GSM transmitter power levels and transmit frequency ok?• See section 3.1. “GSM transmitter power levels and transmit frequency ok?”5.3 GSM Transmitter phase error ok?• See section 3.3. “GSM Transmitter phase error ok?”5.4 GSM (GMSK) modulation spectrum ok?• See section 3.4. “GSM (GMSK) modulation spectrum ok?”5.5 TX power vs. time ok?• See section 3.5. “TX power vs. time ok?”6. DOES THE PHONE HAVE A RELIABLE CONNECTION TO THE NETWORK (WCDMA)?This section means situation when the phone registers to the WCDMA-network and is capable to make a call, but thecall is not reliable even if WCDMA-network field strength is strong. The phone call is maybe disconnected orinterrupted.