Troubleshooting With Rf-Shield Removed; Introduction; Voltage Checking - Nokia RM-627 Service Manual

RM-627
RF troubleshooting

Troubleshooting with RF-shield removed

Introduction

The RF-shield should not be removed in order to replace single components on the RF block. This chapter
only assists in locating the faulty component for statistical purposes.

Voltage checking

Steps
1. Set up the main board in the module jig. The phone should be in local mode.
2. Check the following:
TP#
1 VCTCXO (G7500) supply
2 RFIC Vapaus (N7500) supply from DC/DC
converter
3 TXFEM (N7520) supply from DC/DC
converter
4 WCDMA PA (N7540) supply from DC/DC
converter
5 Vbat at WCDMA PA (N7540)
6 Supply input to DC/DC conv
Note: When using settings as shown in the following Tx Control window, the result at TP4 should
be 3.1V.
Issue 1
Signal name
COMPANY CONFIDENTIAL
Copyright © 2010 Nokia. All rights reserved.
Test point
C7501 2.5V
C7570 2.8V
C7521 1.3V-3.8V (only when transmitting and
depends on output power).
C7528 0.7V-3.1V (only when transmitting and
depends on output power). The value
will be 3.1V when settings as described
in the note below are used.
C7512 3.7V (Vbattery)
C7527 3.7V (Vbattery)
Voltage (all bands)
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