•
The transmitter can be controlled in local mode for diagnostic purposes.
•
The most useful Phoenix tool for GSM transmitter testing is “RF Controls”.
•
Remember that re-tuning is not a fix! Phones are tuned correctly in production
Note: Never activate the GSM transmitter without a proper antenna load. Always connect a 50 Ω
load to the RF connector (antenna, RF-measurement equipment or at least a 2 W dummy load);
otherwise the GSM Power amplifier (PA) may be damaged.
RF Test Points in TX Troubleshooting
Figure 27 RF transmitter & receiver test points
RF Transmitter Self-test
Context
The purpose of RF PA self-test for the phone is to verify the interconnections between RFPA and BCM21351
ASIC.
The self-test will run a series of TX bursts and measure associated Vdet based on different permutations of
the TX control signals. When test is complete it will return either a PASS or FAIL and error report. The signals
including in the coverage can be found in Table 1.
Table 5 Signals Coverage in RFPA Self-test Option
RFPA Signal Name Pin Description Self-Test Coverage
TX_EN Power Amp Enable YES
VRAMP Analog PA Bias/Output Power
Control
YES
TR_SW_EN Transmit/Receive Switch YES
RM-497
RF troubleshooting
Issue 1 COMPANY CONFIDENTIAL Page 4 – 19
Copyright © 2010 Nokia. All rights reserved.
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