Koden MDC-1840BB - Page 162

MDC-1840BB/1841BB/1860BB/1810BB/1820BB Series Chapter 8
Operation Manual Trouble Shooting And On Board Servicing
93142122-07 8-13
Modulator PCB is faulty
N
Y
Ｎ
Y
N
Y
Ｎ
Modulator PCB is faulty
Y
N
Y
Modulator PCB is faulty
+250 V line is shorted
Disconnect J2 from the
Modulator PCB. Is the fault
removed?
Internal wiring in the Antenna
unit or Display unit is faulty
Is the TX drive signal on
TP2 (Modulator PCB)
normal?
Is +24V present on J1-1
pin(Modulator PCB) normal?
Internal wiring in the Antenna
unit or Display unit is faulty
Antenna does not rotate
Replace the fuse
with new one.
Finished
Is the fault
N
Y
N
Motor is faulty.
○
1
Can the antenna be rotated
manually?
Disconnect P4(J4) from the
Modulator PCB. Is the fault
removed?
Check if the following conditions
are observed:
1) The antenna gets caught
with a rope.
2) Turning gear mechanism
g
ets stuck.
Internal wirings in the
Antenna unit or Power
Supply in the Display unit is
faulty
Is the Motor Fuse F2 normal (not blown)?
Waveform on TP2
A
B
5 V
0 V
Pulse length A(ns) B(ms)
SP 100 0.5
M1 200 0.67 or 0.77
M2 550 1 or 1.25
LP 1050 2 or 2.5
Pulse selection
function is faulty