User Guide

RM-94
Nokia Customer Care 6(b) - RF Troubleshooting
14 COMPANY CONFIDENTIAL Issue 1 04/2005
Copyright © 2005 Nokia. All Rights Reserved.
No
Check supply filter
components (R7511,
C7524) and UEM
Oscilloscope:
Check reference voltages of RF part:
VrefRF01 = 1.35V ?
(TP: VrefRF01*)
Yes
Receiver
Fault Finding Tree
part 4
Oscilloscope:
Check reference voltages of RF part:
VrefRF02 = 1.35V ?
(TPs: VrefRF02* and VrefRF02**)
Yes
No
Check supply filter
components (R2900,
R2901, C2900, C2901)
and UEM
Spectrum Analyzer:
1)
Check Rx/Tx Switch (Diplexer)
Depending on selected band, check level at TPs:
GSM900 output Rx1 Pref -1.5dB ?
GSM1800 output Rx2 Pref -2.0dB ?
GSM1900 output Rx3 Pref -2.5dB
?
Yes
Change Z7800
No
Note
1)
:
RF levels are dependent on RF probe and have to be validated
with a known good sample.
Receive
r
Fault Finding Tree
part 5
Signal Generator:
To be tuned that input power at spectrum
analyzer: –60dBm
(power at probe:
Pref
= approx. -63 dBm)
Frequency: calculated from Phoenix
offset: 67.71kHz
Phoenix:
Phone: local mode
RF Controls
:
Active Unit: Rx
Op. Mode:
Continuous
Rx/Tx channel: default (mid)
AGC: 14
Yes
BB error:
Check UPP
Oscilloscope:
RF-BB serial interface ok?
(TPs: RFBusData, RFBusClk, RFBusEna1)
Oscilloscope:
RX IQ levels ok (TPs: RXI, RXQ) ?
No
Change RF
ASIC (Helgo)
Change RF
ASIC (Helgo)
Yes
Receiver
Fault Finding Tree
part 6
No