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NSD–1
Disassembly / Troubleshooting Instructions
PAMS Technical Documentation
Page 25
Issue 2 09/00
Nokia Mobile Phones Ltd.
AMPS Tuning RSSI
Description of Test
Changing the AMPS receiver input level results in different Gains in the
Limiting amplifier in RIF to produce a limited output. This test measures
AMPS RSSI with high receiver input signal and low receiver input signal,
and then stores these values to eeprom. WinTesla will prompt with what
level to set going into the receiver.
Definition of Result
The reported result is the ADC value from CCONT. For RSSI Lo the result
should be between 570 and 970 and is stored to eeprom under the han-
dle RF_TUNE_AMPS_RSSI_LO_HANDLE. For RSSI Hi result should be
between 750 and 1050 and is stored to eeprom under the handle
RF_TUNE_AMPS_RSSI_HI_HANDLE.
Manual Verification
Use WinTesla as follows:
Trouble Shooting
Check components in the AMPS receiver chain starting with the Duplexer
Z701, Down Converter IC N703, 128.55MHz IF SAW filter Z702, 450KHz
Ceramic filters Z706 and Z708 and RIF N702. Check the Rx VHF LO RIF
N702 Pin 20 (TP107) see below. Also check RIF 450KHz output LIM_P
Measured at RIF Pin 17 (TP108) and the RSSI voltage at RIF N702 Pin
16 (TP109) which indicates the signal level into the receiver.
Rx VHF LO Measured at RIF N702 Pin 20 (TP107) with a Hi Z Probe: