Denon DR-M22 - Maintenance and Adjustments; Mechanism Section Adjustments and Checks

ADJUSTING AND CHECKING THE MECHANISM
SECTION
1. Replacing the Pinch Roller 23 and 104
Before replacing the pinch roller, clean the tape contact
surface of the pinch roller and the capstan shaft.
Most causes of poor tape transport can be traced to dirty
pinch rollers and capstan shafts.
The right side pinch roller 23 can be taken out by remov-
ing spring 24 and slit washer 317. In the same manner,
the left side pinch roller 104 can be taken out by remov-
ing spring 106 and slit washer 317. After replacing, play
a padless C-90 tape and check for tape curls at the head
tape guide section.
In addition, in the playback mode, check to make sure
that the right side pinch roller contacts the capstan shaft
before the left side pinch roller contacting.
Correct P. Roller arm L
ra
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(E22)
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a
U
id
Tape
guide
P.
RollerarmR
2nut E. head
2 nut
R/P head
Special nut
Defective Sales Gaied
Tape travel
2. Checking the Pressure Force of the Pinch
Roller
In the playback mode, hook a spring weight onto the
bracket at the center of the pinch roller. After separating
the pinch roller from the capstan shaft, allow the pinch
roller to contact the capstan shaft again. When the pinch
roller starts to rotate, check to make sure the rod type
spring weight reading is 350g—450g for the right side and
150g ~ 250g for the left side.
If it is not within the normal range, replace the pinch
roller spring 24 or 106.
Pinch roller spring
Capstan shaft
Pinch roller
Right side
350g ~ 450g
Left side
150g ~ 250g
3. Replacing the Record/Playback Head
* Before replacing, remove the front panel 233.
(1) How to remove the R/P HEAD.
1) Next, Take out the azimuth adjustment NUT 311,
tilt adjustment NUT 311, and the height adjustment
ORDER SCREW 10 loosening them alternately.
If they are not loosened alternately, the R/P HEAD
base may become warped.
2) By unsoldering the HEAD WIRES on the circuit board
section of the R/P HEAD, the entire R/P HEAD
can be taken off the mechanism unit.
C@ R/P head
ue
(Azimuth adj..nut)
(Tilt adj. nut)
(2) How to assemble the R/P HEAD.
Reverse the above (1) procedures for removing the R/P
HEAD.
*Solder the HEAD WIRES according to the diagram
above. 2
Red
Yellow
4. Adjusting the R/P HEAD
(1) Height adjustments (Use the head adjusting jig M-300)
1) Set the M-300 tool plate on the mechanism unit; turn
the height adjustment ORDER SCREW 10 and adjust
so that the 3.8 mm measure section ofthe M-300 (tool
grip) can pass without contacting the tape guide of
the R/P HEAD 9.
2) When adjusting the height, make sure the R/P HEAD is
not tilted by turning the azimuth adjustment nut 311
nut, and checking with your eyes.
* Never allow the M-300 (tool grip) to hit tthe tape contact
surface of the R/P HEAD strongly. It may scratch the
surface.
ae by Dee