Receiver Fault - Nokia NSE–3 SERIES Service Manual

NSE–3
Disassembly & Troubleshooting Instructions

Receiver Fault (4)

COBBA
N250 pin 7,12,21,25 and 63,
~2.8V
YES
N250 pin 27 and 53,
~2.8V
YES
N250 pin 9,
~1.5V
YES
N250 pin 10,
loading 100 k
YES
N250 pin 45,
13 MHz clock OK
YES
N250 pin 28,
is "HIGH"
YES
Check data and adress lines
between D200 and N250, if
OK change N250
COBBACLK – signal:
Oscilloscope picture in Appendix A
Page 24
NO
Check VCOBBA–voltage from
NO
Check VBB–voltage from
NO
Check VREF–voltage from
CCONT pin 13 through R253
NO
Check soldered joints and
Ω
NO
Check COBBACLK–line from
NO
Check COBBARSTX–line
Technical Documentation
CCONT pin 22
CCONT pin 55
R253
MAD pin 144
from MAD pin 163
PAMS
Original, 11/97