Nokia RM-42 Service Manual

Also see for RM-42: Service manual

Contents

Nokia Customer Care Appendix A: RF TroubleshootingA-72Company ConfidentialCopyright © 2005 Nokia. All rights reserved• Spectrum analyser RBW = VBW = 10 MHz, Span ≤ 2 MHz, sweep time 100 ms.• Connect the RF probe to R7520. The RF-level should be about the same on both ends of theresistor. Check output level with 0 dBm power level (Set start level “0” to Phoenix).- Power level “0” – Output level should be about -40…-48 dBm4.1.1.1.1 RF operating voltage VBAT_ASIC ok?• See section “RF operating voltage VBAT_ASIC ok?”4.1.1.1.2 RFBUS signals ok?• GSM receiver has to be active before RFBUS signals can be measured. Procedure is explained insection “GSM RX chain activation for manual measurements”. Also WCDMA/GSM transmitter andWCDMA receiver activation can be used for the measurement but then RFBUS -signals don’tnecessarily look like in figures mentioned below.• Measurements can be performed with an oscilloscope and a probe. Check all five RF BUS signals:- RFBUSDAT: Connect the probe to J7504. Typical RFBUSDAT -signal is shown in section 6.5.9.3“RFBUSDAT (GSM RX)”- RFBUSCLK: Connect the probe to J7505. Typical RFBUSCLK -signal is shown in sections 6.5.9.1“RFBUSCLK (GSM RX)” and 6.5.9.2 “RFBUSCLK and RFBUSENA (GSM RX)”- RFBUSENA: Connect the probe to J7506. Typical RFBUSENA -signal is shown in section 6.5.9.2“RFBUSCLK and RFBUSENA (GSM RX)”- RXRESETX: Connect the probe to J7515. RXRESETX -signal is a constant 2 V DC-signal after GSM orWCDMA transceiver has been activated the first time after phone boot up. The level of this signalshould be about 0 V before transceiver activation.• TXRESETX: Connect the probe to J7517. TXRESETX -signal is a constant 2 V DC-signal after GSM orWCDMA transceiver has been activated the first time after phone boot up. The level of this signalshould be about 0 V before transceiver activation.4.1.1.1.2.1 RAP3G (or Vinku or Hinku) faulty?• RAP3G (D2800) cannot be replaced.4.1.1.1.3 Vinku (N7501) regulator voltages VREG1, VREG2 ok?• WCDMA transmitter has to be active before VREG1 and VREG2 voltages can be measured. Procedureis explained in section “Transmitter 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)