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MDC-2900 Series
Chapter 4 Troubleshooting and on-board repair
0092629012-07
4-19
Does the antenna rotate
normally after having
changed a motor fuse?
Is the motor fuse
in the Display
normal?
When the antenna rotation is set to
regular rotation (24rpm), observe
"MENU> SYSTEM> BITE> RATE OF
ROTATION".
Is the rotate fast?
Is the rotate slow?
In the Antenna unit, the MOTOR (-) wire of the
motor and housing case short-circuit, or
Modulator PCB is failure.
A rope coils itself around an antenna. Or motor
brushes decrease.
Change motor brushes with new set.
Go to [5.1.2 Annual inspection] in page 5-1
Does the antenna rotate?
Normal
When pull connector P2
in the ANT connecting
cable, are the resistance
values between J2-5 and
J2-7 less than 500k
Ω
?
Confirm the following and
deal.
1. A rope coils itself around
an antenna, and does not a
turn lock it?
2. Do not motor brushes
decrease?
3. Is not a motor failure?
A motor power supply in the
Modulator PCB is failure.
Normal
When pull P4 in the
Modulator PCB and
did on of a motor
power supply, is the
voltage between
J4-4(+) and J4-5(-)
11+/-2V?
Rotary is abnormal.
A motor power supply in the
Modulator PCB is failure.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
4.3.2.13 Rotary abnormality