JVC D-M3 - Page 5

Dimensions
| D-M3 A/B/C/E/J/U
Unit; mm
7 130.5
n wo
wow
er
y ei
Front
Fig. 6
Safety Precautions
A Safety mark
Safety is very important with this unit. When replacing the
parts marked A , be sure to use only those designated
parts. The designated resistors, diodes, transistors become
hot in use. When replacing, be sure to secure them with a
distance of more than 5 mm from the circuit board. In addi-
tion, they are banded together to avoid touching other wir-
ing, recheck this point as well after repair.
The wiring of the primary side should be wound more than
one and half times, then soldered.
Maintenance
To get long, trouble-free service, maintenance is important.
Do not forget cleaning and demagnetizing.
Cleaning
After long use, the heads and tape part — capstan, pinch
roller, etc. — will become dirty with dust or magnetic
particles. Dirty heads cause imperfect erasing or high fre-
quency drop-off. A dirty capstan and pinch roller will cause
unstable tape speed, leading to increased wow and flutter.
Always keep them clean by following the procedure below.
1. Heads
Use the head cleaning stick provided to wipe the surface
where the tape comes into contact with the head.
(It is effective to moisten the cotton with alcohol.)
2. Pinch roller and capstan
Do the same method as heads.
3. Cabinet
When the cabinet becomes dirty, wipe it with a soft cloth
soaked with a neutral cleaning solution of a polishing cloth.
* Do not use thinner or benzine.
Minimum
5 mm
To protect the circuit board
from carbonized under
abnormal condition.
Demagnetizing
The heads are made from a material resistant to magnetiza-
tion, but after long use they become magnetized.
A magnet brought into their vicinity can magnetize the
heads, causing excess noise. If noise seems to have in-
creased, demagnetize the heads with a head demagnetizer
through the following procedure.
1. Turn the POWER switch OFF.
2. Wrap the tip of the demagnetizer with vinyl tape or soft
cloth so as not to damage the head surface. Switch on
the demagnetizer and bring it close to the head.
3. Move the tip of the demagnetizer slowly first to the left
and right, then up and down in front of the head.
Gradually move it away from the head and switch it off
at a distance of more than 30 cm. (12”)
4. The erase head need not be demagnetized. The capstan
shaft and tape guide should be demagnetized in the
same way as the record/playback head.
* Do not bring a magnetized metallic object (a screw-
driver, for example) near the head as this will increase
noise.
No. 4213