Drive Mechanism
GV 900…, GV 940…
k
5 - 16
GRUNDIG Service
englisch • English • anglais
Mechanical Troubleshooting
1. FF/REW or PB Failure
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Is master cam acc. to the
operating mode in fast
forward or playback position ?
Does loading
motor operate?
Modes changing smoothly
through master cam?
Check loading motor control
system.
Are Vco 12V and
Vcc 5V applied?
Check the capstan motor.
Press
Ï
,
Ì
or
Å
button.
Check the idler ass’y.
Check the reel sensors.
Is voltage applied
to loading motor?
Check voltage supply.
Check the loading motor.
Check voltage supply.
Check master cam position or
master cam sensors.
Does capstan motor turn
acc. to the operating mode?
Does idler wheel turn?
Are tacho pulses fed out from
reel sensors?
Check cassette or check signal
path in Playback/Record mode.
2. Failure of video search reverse mode
Is Playback function normal?
Press
Ï
button.
Master cam shifting to video
search reverse position?
Go to 1. FF/REW or PB
FAILURE routine.
Check idler gear ass’y.
Check limiter pulley ass’y.
Check reel sensors.
Go to 1. FF/REW or PB
FAILURE routine.
Does idler wheel turn?
Is supply reel winding
torque correct?
Are tacho pulses fed out
from reel sensors?
Check playback signal path.
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Check loading motor.
3. Unusual noise in cassette insertion and ejection mode
Yes
Yes
No
No
Unusual noise in cassette
insertion and ejection mode.
Is unusal noise heard when
the cassette compartment
is moved?
Is unusual noise heard with
pinch roller lever going
up or down?
Is unusual noise heard during
the threading and
loading function?
Check pinch roller drive cam,
pinch roller drive lever and reverse
guide.
Check cassette control ass’y.
Yes
Yes
No
No
No
No
Yes
Yes
Check capstan motor.
4. Unusual noise in FF/REW mode
Is reel height as
specified?
Is noise heard when turning
the reel by hand?
Does the drive mechanism
touch any part on the chassis?
Is noise heard when turning
the capstan motor by hand?
Check the following parts of
the drive mechanism:
• Reel
• Limiter pulley ass’y
• Idler wheel ass’y
• Gears of drive mechanism
Check the reel gearwheels
and main chassis board.
Adjust reel height.
Rearrange the parts on
the main chassis board.
