PAMS
Technical Documentation
NSE–3
Disassembly & Troubleshooting Instructions
Page 24
Original, 11/97
Receiver Fault (4)
COBBA
N250 pin 7,12,21,25 and 63,
~2.8V
Check VCOBBA–voltage from
CCONT pin 22
N250 pin 27 and 53,
~2.8V
Check VBB–voltage from
CCONT pin 55
N250 pin 9,
~1.5V
Check VREF–voltage from
CCONT pin 13 through R253
N250 pin 10,
loading 100 k
Ω
Check soldered joints and
R253
N250 pin 45,
13 MHz clock OK
Check COBBACLK–line from
MAD pin 144
N250 pin 28,
is ”HIGH”
Check COBBARSTX–line
from MAD pin 163
COBBACLK – signal:
Oscilloscope picture in Appendix A
Check data and adress lines
between D200 and N250, if
OK change N250
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
To Next Page
Loading...
