GRUNDIG GV94NIC Repair Manual

GV 94 �Drive Mechanism
Note:When refitting the tape drum (Pos. 11000) align it to match
9. Adjustments
with the two dowels Y of the mounting base on the mecha-
nism chassis (Fig. 8.38).9.1 Adjusting the Brake Band
Tighten the screws (Pos. 10400) using a torque of 3.9 to� Activate the Service Test Mode (refer to point 6) and position the drive
4.2 kg/cm.mechanism so that it is in PLAY/STOP mode (display shows 05).
� Set the brake band adjuster A so that the tip of the lever
(Pos. 40100) is between the two lines on the mechanism chassis
(Fig. 9.1).
Checking the back tension:
� Play the torque meter cassette in PLAY mode.
11000Y allemand
� Check that the back tension torque is 30� 50g/cm.
Tape drum
Adjust the tip of the lever
between the two lines
German
Y
deutsch
YDowels
A
10400
10400Screw
Screw
Fig. 9.1
Fig. 8.38
9.2 Checking the Reel Winding Torques (Fig. 9.2)
� Dismantle the cassette mechanism (see point 8.1).
Note:On reassembling the rotor (Pos. 21000) the phase must be
� Cover the start-of-tape and end-of-tape sensors.
adjusted to that of the headwheel. The hole W of the
� Put the torque meter with the adapter on to the left or right reel and
headwheel and the hole X of the rotor (Pos. 21000) must be
set it to 0.
on the same side as shown in Fig. 8.39.
� Measure the torque of the right reel in A mode after 10 seconds, and
Tighten the screws (Pos. 30000) for attaching the rotor
check that it is between 60 and 110g/cm.
(Pos. 21000) and the stator (Pos. 22000) using a torque of
� Press the I button in PLAY mode. Measure the torque of the left
2.5 to 3.5 kg/cm.
reel. The value must lie between 115 and 180g/cm.
11200
Headwheel
WHole
21000
Motor rotor
XHole
Fig. 9.2
9.3 Adjusting the Tape Path
Fig. 8.39
When one of the parts shown in Fig. 9.3 has been removed or replaced,
do not fail to check and adjust the tape path. The tape path is adjusted
while observing the envelope waveform of the video head output
signal.
GRUNDIG Service5 - 29