Smiths Kelvin Hughes Nucleus 3 5000 Series, System Handbook

Page: 379 / 510

Original 7d.23/24 May 01
KH 2020
Chap 7d
CD-4192
SET TO LONG PULSE
NO SYNC
NO VIDEO
(MODULATOR FIRING)
POOR SIGNALS
BUT NO WARNING FOR
‘NO VIDEO’ SHOWING
ARE CO-AXs OK?
YES
ARE RECEIVER
CONNECTIONS OK FROM
LOW NOISE FRONT END
& CABLEFORMS?
NO
YES
REPAIR CONNECTIONS
LOGARITHMIC RECEIVER PCB
FAULT OR TUNE INPUT FROM
DISPLAY NOT WORKING
REPAIR CO-AXs ARE CO-AXs OK?
IS CONTROL
BOARD LED D43, LIT?
(HEATER OK)
INTERCONNECTION OR
MAGNETRON HEATER SHORT
OR PSU FAULT
IS D23 LIT, ON THE
MODULATOR PCB?
NO
YES
NO
YES
NO
YES
IS
MODULATOR FIRING
A CONTINUOUS AUDIBLE
NOTE AT SELECTED
PRF?
NO
YES
IS
MODULATOR FIRING
AN INTERMITTENT NOTE?
NO
YES
MODULATOR FAULT
AT RUN,
IS D24 (300V ACTIVE) LED
MODULATOR PCB LIT?
NO
YES
CABLEFORM MODULATOR
OR MICROCONTROLLER PCB
FAULT OR NO TRIGGER
FROM CONTROL BOARD
CHECK MODULATOR PLA
CONNECTOR OR FOR A
CONNECTION FAULT TO
CONNECTOR IF SO REPAIR,
OTHERWISE MODULATOR FAULT
ALSO CHECK Tx MICRO
CONTROLLER PCB PLS (SYNC 1)
PLT (SYNC 2)
IS D23 (300V UNSAFE)
LED ON MODULATOR LIT?
NO
YES
POWER SUPPLY OR
MODULATOR PCB FAULT
MODULATOR MV SMPS FAULT
OR NO RUN COMMAND
FROM CONTROL BOARD
NO
SWITCH MON ON
AT 12 MILE RANGE
IS Tx MON
PLUME GOOD?
(FOR RADIUS SEE
RADAR LOG)
NO
YES
POOR MAGNETRON
OR WAVEGUIDE
ANTENNA PROBLEM
ARE Rx MON
FINGERS GOOD?
(FOR RADIUS SEE RADAR
LOG . ADJUST TUNE
FOR STRONGEST
SIGNAL)
YES
NO
IF MUCH SHORTER THAN LOG
FAULTY LIMITER,
LNFE OR RECEIVER OR
TX MICROCONTROLLER PCB
OR WIRING BETWEEN
THESE UNITS
SIGNAL STRENGTH NOT
AFFECTED BY TUNE CONTROL.
TUNE INDICATOR
NOT WORKING.
YES
NO
LNFE OR LOGARITHMIC
RECEIVER PCB FAULT OR
TUNE INPUT FROM DISPLAY
TO RECEIVER FAULT
Tx MICROCONTROLLER PCB
OR CONNECTION FAULT
IS Tx
MICRO CONTROLLOR PCB,
D18 (TUNE) LED LIT?
FAILURE MESSAGE
- NO SYNC
- NO VIDEO
OR NO MESSAGE
FROM SHEET 1
IS D22 LIT, ON THE
MODULATOR PCB?
NO
YES
27V TO MODULATOR
MISSING
CHANGE SWITCH S1
REPAIR CO-AXs
NOTE:
CORRELATOR
MUST BE OFF
Figure 10d - Flowchart (sheet 2 of 2) Figure 10d (Sheet 2)