User Guide

NPL-4/5 Company confidential
Troubleshooting Instructions Nokia Customer Care
Page 20 Copyright © 2004 Nokia Corporation. All rights reserved. Issue 1 05/04
Measuring analogue RX I/Q signals using oscilloscope
Measuring with an oscilloscope on “RXIINN”, (R421) or “RXQINN”, (R423) is recom-
mended only if RSSI reading does not provide enough information. Input level = -60dBm.
- Start Phoenix Service Software and open FBUS connection.
- Select → Scan Product (Ctrl-R)
Wait until phone information is shown in the lower right corner of the screen.
- Set operating mode to “local mode”
- Select → Testing → RF Controls
Wait until the RF Controls window is popped up.
- Select → Band →GSM 850 or GSM 900 or GSM1800 or GSM1900
Active unit → RX
Operation mode → continuous
RX/TX Channel → 190 or 37 or 700 or 661
AGC → 12
Following diagram should be displayed on an oscilloscope' s screen if the GSM 900
receiver is working properly:
Figure 10: Signal Amplitudes