Denon DRR-M31 - Page 5

5
5DRR-M31
ADJUSTMENTS
6
1. Replacement of the pinch roller
Before replacing the pinch roller, clean the tape contact
surface of the pinch roller and the tape contact surface of
the capstan shaft. After replacement, run a C-90 tape
without a pad and check for the presence of tape curl at
the tape guide portion of the head.
ADJUSTMENTS
Adjusting and Checking the Mechanism Section
2. Checking the pinch roller pressure
Set to the playback condition and hook a bar-type spring
scale to the bracket above the center line of the pinch
roller. Pull the pinch roller away from the capstan shaft,
then allow the pinch roller to come into contact with the
capstan shaft and check that the reading of the bar-type
spring scale is between 2.45 N~3.92 N (250~400 g) when
the pinch roller starts to rotate or pull force indicates more
than 7.85 mN (80 g).
Replace the pinch roller when the value falls outside of
the specified range.
3. Replacement of the recording/playback head
assembly
3-1 Removal of the head assembly
(1) Remove the 2 BRACKET-HEAD fastening screws.
(2) Remove one screw fixing P.W.B.
3-2 Mounting the recording/playback head assembly
Perform by following the steps of Section 3-1
Removal of the head assembly in reverse.
4. Adjustment of the recording/playback head
Azimuth adjustment
Load side A of the A-BEX TCC-153 test tape facing
forward, and adjust.
(1) Play in the FWD direction and turn the azimuth
adjustment nut for the FWD side so that the
Lissajous’s figure becomes maximum at (A) and
minimum at (B).
(2) Play in the REV direction and turn the azimuth
adjustment nut for the REV side as adjusting the
FWD side method.
(3) Adjust (1) and (2) again.
(4) Apply screw lock to the adjustment locations.
5. Checking the winding torque
Load a cassette type torque meter (Sony TW2111A at
the FWD side) and check that the reading of the torque
meter during playback is
294 to 686 mN-cm (30 to 70 g-cm) at the center value.
2.45 3.92N
(250
400g)
Capstan shaft
Pinch roller
LINE OUT
PB Amp
A-BEX TCC-153
V
H
L
R
B
REV SIDE
REC/PB HEAD
A
FWD SIDE