MDC-1840BB/1841BB/1860BB/1810BB/1820BB Series Chapter 8
Operation Manual
Trouble Shooting And On Board Servicing
93142122-07
8-7
5. Faulty radar picture
Y
Y
Y
N
Ｎ
Y
HM PCB is faulty
Modulator PCB is
N
N
Y
N
Y
N
Y
Main Logic PCB is faulty
Is the radar echo displayed?
Y
N
Y
N
Main Logic
PCB is
faulty
Y
Ｎ
Is background noise
present at Gain max
position?
Is the error message
“RADAR VIDEO
ABNORMAL” shown?
Go to “9. Antenna faults,
Radar echo abnormal”
Main logic board is faulty
Is the receiver sensitivity
normal throughout the
entire range scales?
Go to “9. Antenna faults,
Radar echo abnormal”
Is the receiver
sensitivity low in long
ranges?
Is the TX Drive signal on
TP2 on Modulator PCB
correct?
Go to “9. Antenna
faults, Pulse selection
not operative”
N
Does the sweep line
skip near the HM
(Heading Marker)?
Does the antenna
rotate freely?
Is the error message
“HEADING LINE
ABNORMAL”
shown?
Go to “9. Antenna
faults, Pulse selection
not operative”
Is the error message
“AZIMUTH ABNORMAL”
shown?
