Chapter 8
MDC-1840BB/1841BB/1860BB/1810BB/1820BB Series
Trouble Shooting And On Board Servicing
Operation Manual
8-6
93142122-07
3. No display
4. Antenna does not respond
N
Y
Y
Ｎ
LCD Monitor unit is faulty
N
Ｎ
Y
Y
Y
Power Supply PCB is
faulty
N
Y
Ｎ
Y
Performance Monitor
is faulty
Y
N
Y
N
Modulator PCB is faulty
N
Y
N
Correct the faulty cable connections
Are the cable connections
between J728, 729 (Main
Logic PCB) and LCD
Monitor correct?
Main Logic PCB is faulty
Check if the status of
LEDs on the Main Logic
PCB is as follows’
1) DS1:
ON
2) DS2:
ON
Is the error message
“ANTENNA NO
RESPONSE” shown on
the screen?
Main Logic PCB is faulty
Is +12V on J701-20 pin
and GND normal?
Disconnect Antenna
Connector J1 and check
if +12V on J701-20 pin
becomes normal.
Connect J1
Is +12V present at
J2-2 in Antenna unit?
Disconnect Modulator
Connector J6 and
check if +12V on
J711-3 pin is normal.
Disconnect
Modulator
Connector J4
and check if
+12V at J711-3
pin becomes
normal.
Modulator PCB
is faulty
Modulator PCB is faulty
Is +5V on J5-12 pin
in Modulator Unit
normal?
Are the antenna cable
connections at Antenna
and Display units correct?
Modulator PCB or Main Logic
PCB is faulty.
Correct faulty connections
Y
Y
Y
