Nokia 6610 - Page 10

NHL-4/4U Company confidential
Troubleshooting Instructions CCS Technical Documentation
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HELGA
troubleshooting
Baseband
troubleshooting
Synthesizer
troubleshooting
Check with oscilloscope:
-TXI/TXQ signals
--VR1, VR2, VR4, VR5, VR6 = 2.8V
-VrefRF01 = 1.35 V
-HELGA serial interface
-TXP & TXC signals
OK ?
No
Check with RF probe:
-4G VCO out signal
- 3589.6 MHz (GSM900)
-3495.6 MHz (GSM1800)
- 3760 MHz (GSM1900)
Level >-10dBm (*
OK ?
No
dead
Replace HELGA
Yes
Check modulator
output components
OK ?
Replace
faulty
component(s)
*(When 1kOhm passive probe is used,
correct the measurement result by +26dB