User Guide

Nokia Customer Care
Appendix A: RF Troubleshooting
A-72
Company Confidential
Copyright © 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 the
resistor. Check output level with 0 dBm power level (Set start level “0” to Phoenix).
- Power level “0” – Output level should be about -40…-48 dBm
4.1.1.1.1 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 in
section “GSM RX chain activation for manual measurements”. Also WCDMA/GSM transmitter and
WCDMA receiver activation can be used for the measurement but then RFBUS -signals don’t
necessarily 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 or
WCDMA transceiver has been activated the first time after phone boot up. The level of this signal
should be about 0 V before transceiver activation.
• TXRESETX: Connect the probe to J7517. TXRESETX -signal is a constant 2 V DC-signal after GSM or
WCDMA transceiver has been activated the first time after phone boot up. The level of this signal
should 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. Procedure
is 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)