Motorola i897 - RX Analysis Test

TROUBLESHOOTING: RX Analysis Test
3.6 RX Analysis Test
Use this test on a unit to perform a RX analysis in iDEN mode.
1.
Set up the R-2660 as follows: Mode: iDEN Test, Meter: RF DISPLAY, RF Control: GENERATE, FREQ: (See
Table) MHz, Gen: OUT6/6, Gen: -60 dBm, RF I/O.
2. Set the spectrum analyzer to Center Freq: 851.000 MHz (935.01875 MHz for 900), Span: 100 kHz, Amplitude:
-30 dBm reference level. Set marker to test frequency, and use Trace and Max. Hold to obtain readings. Use Clear
before taking each reading.
3. Except as noted, use a 50-ohm probe for all RF measurements. The probe ground must make contact with the
board ground during the measurements.
4. Check that signal measurement levels are +3dB at each test point, unless otherwise stated. A low RSSI level will
result in higher BER as the signal becomes weaker.
5. The RF cable from the R-2660 to the unit under test (UUT) should be <18 in. for these measurements in this flowchart.
6. Be sure to check for any defects, such as unsoldered connections, shorts, broken or defective components.
7. Remove the antenna from the UUT before beginning these tests.
Do voltages
agree with
table
+5%?
Inject a -50 dBm CW tone into the RF
jack at the selected frequency from the
table with a frequency offset (+ 2KHz).
Place Radio into BERBUG, and send the
following commands: RX STATIC
RX FREQ XXX ( XXX is one of the
frequencies from the table) MODE RX
For the programmed frequency, measure
voltages on the capacitors in the table.
Check R760, R759, R758 for S,
US, MP and DFP then if no fault remove the
three resistors from the board and measure
the voltages on the Roadrunner
side of the resistor.
Yes
No
Were all
frequencies from
table tested?
Yes
No
Abbreviations:
S - check for Shorts
US - check for unsoldered parts / open connections
MP - check for missing parts
DFP - check for defective parts
Do
voltages
agree with table
+5%?
Check the voltages on positive
terminal of C212
( negative terminal always 0V)
Check R760, R759, R758 for S,
DFP.
Check DC section, then if no fault
found replace the
Roadrunner IC (U700).
Frequency GP03- GP04- GP05-
(MHz) R760 R759 R758
Voltage Voltage Voltage
860 0 2.775 2.775
915.525 2.775 0 0
937.49375 2.775 0 2.775
No
Are voltages
2.775 V
+5%?
Check C212, R212 and C214 for S, DFP.
Check DC section, then if no fault
found replace the
Janus Module (U500).
Yes
Check DC section, then if no fault
found replace the
Roadrunner IC (U700).
No
Measure DC voltages on TP_RXI,
TP_RXIX, TP_RXQ, TP_RXQX.
Yes
A
Continued
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