Receiver Fault - Nokia Mobile Phones NHX-4N Troubleshooting Instructions

PAMS
Technical Documentation

Receiver fault

Receiver fault
See earphone level fault
FAIL
Simplex sens.
N370/9 (DAF) OK?
(TX off)
OK
FAIL
Transmitter
TX spectrum
fault
OK
Replace duplex
filter Z660
RX–VCO
oscillating
OK
VCO–freq
OK
Check: RXINJ level at V341
collector (5–10 dBm), V341
operating voltage and bias, C341
Original, 01/98
OK
AF signal at
FAIL
FAIL
Check: operating voltage of
G530
Check: resistance through
N820/3, R521, R522, R523
FAIL voltage N820/4,14
Connections of R530, C532
VCTCXO operating voltage
and frequency = 14.85 MHz.
Check SCLK, SDAT and SLE
lines.
Disassembly & Troubleshooting Instructions
FAIL
VCCR, VREF,VSYN
OK?
OK
OK
RXINJ
at N370/16
OK at V341
collector
FAIL
FAIL
after Z350
FAIL
Check: solderings of
Z660, Z321, Z350
operation of V320
NHX–4N
Check: V310, V311
V313, V314,
N101/4
1. IF
OK Check: voltage of N370/4,
components C378, R371,C377,
OK? Z370, L370,
if OK replace N370
IF level
OK
Check operation
of V380
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