Troubleshooting Chart For Pll Synthesizer - Nokia NPM-10 Series Troubleshooting Instructions

CCS Technical Documentation

Troubleshooting Chart for PLL Synthesizer

From Phoenix chose:
File > Choose Product > NPM-10
Mainenance > Testing > RF Controls >
GSM1900 > RX > continuous > Ch 661
Spectrum Analyzer
VCO frequency
(R656)
3920.0 MHz
Oscilloscope
VCXO Power
Supply (C620)
2,7 V
Yes
Oscilloscope
VCXO output
(R420) 26 MHz,
approx. 700mVpp
Yes
Oscilloscope
VCO Power Supply
(R656)
2,7 V
Yes
Oscilloscope
PLL Power Supply
(C665 & C634)
ALL 2,7 V
Yes
Yes
Spectrum Analyzer
VCO output (R656)
Some signal
between 3 and 4
GHz
No
VCO (N601) is not
If the phone stops working a short time after the power is turned ON, a possible reason
for this might be that the 26 MHz system clock signal is not getting to the UPP clock-
input in Baseband. In this case, check the following:
Turn on the phone and check
700mVpp
If this is not the case check the reference crystal (B600), Mjoelner (N600), R420, R426,
C420, and C426.
Issue 1 03/2003
Yes
PLL block functional
No
No
Check UEM, Software??
Phone not in function
No
VCXO is not functional
Check Crystal (B600)
No
Check UEM, Software??
Phone not in function
No
Check UEM, Software??
Phone not in function
Yes
functional
Figure 23: PLL troubleshooting chart
VCXO Power supply (C620) = 2.7V
VCXO output (R420 – end not connected to C420) is 26MHz and approx.
Nokia Corporation
Troubleshooting Instructions RF
Oscilloscope:
Measure
No
Loopfilter R618,R619,
Control Voltage C641
between 0.5 and 4.0 V
Yes
Check
Mjoelner N600,
UPP D400,
RFBusClk J608,
RFBusDA J610,
RFBusX j609
& Reset_Mjoel
Confidential
NPM-10
Check
C639-C641
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