Nokia RM-12 Troubleshooting Instructions page 10

RM-12
HELGO IC
troubleshooting
Check with oscilloscope:
-TXI/TXQ signals
-VR1, VR2, VR4, VR5, VR6 =2.8V
-VrefRF01 = 1.35V
-Helgo serial interface
-TXP & TXC signals
OK?
Yes
Check with RF probe:
4G VCO signal output:
-3589.6MHz (GSM900)
-3495.6MHz (GSM1800)
-3760MHz (GSM1900)
Level > - 10dBm
OK?
Yes
Check modulator output components
OK?
No
Replace faulty
component(s)
Issue 1 11/2004
Figure 4: HELGO IC troubleshooting
No
No
Yes
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Copyright © 2004 Nokia. All Rights Reserved.
CCS Technical Documentation
Baseband
troubleshooting
Synthesizer
troubleshooting
Replace HELGO
8