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NSD–1
Disassembly / Troubleshooting Instructions
PAMS Technical Documentation
Page 31
Issue 2 09/00
Nokia Mobile Phones Ltd.
Trouble Shooting
Check that the RX_GS line on the up–converter N703 Pin 15 (TP111) is
changing from high to low. If this is and the Gain does not change signifi-
cantly then the Up–converter IC N703 is probably faulty and should be
replaced.
800 CDMA Tuning Rx IF AGC
Description of Test
The RIF and TIF AGC is approximately a second order curve, this curve
is split into 16 segments for both Transmitter and Receiver. Offset and
slope values are stored in eeprom for each of these 16 segments. The
offset for the segments are computed from the 3–point calibration per-
formed in this test. After test a 2
nd
order approximation is made and the
Offset and Slope are computed.
This tuning is done by putting signal level 1 into the receiver, the
RX_IF_AGC will then automatically adjust for max CAFÉ input and the
RX_IF_AGC is noted. This process is then repeated for signal levels 2
and 3.
Definition of Result
The results of the 3 point tuning are the 16 slope and offset values, which
are stored to eeprom RF_TUNE_CELL_RX_AGC_OFF-
SET_SLOPE_HANDLE.