Hitachi DV-RV8500E, Service Manual

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Adjustment / Maintenance > Maintenance
(4) Problem guide
If the time of using the VCR exceeds approx. 1,000 hours, the phenomena shown in Table 5-4-1 may
appear on playback images. These phenomena may disappear when the mechanical components are
cleaned or lubricated. Check the use time, etc., and if judged that it is time for maintenance and
inspection, inspect the portions to be checked according to Table 5-4-1.
Note:
If normal operation is not restored after cleaning, the components marked in component
replacement column probably need to be replaced, since their performance may be degraded.
Table 5-4-1 List of phenomena
Phenomenon
Color beats
Poor S/N, no color
Vertical jitter,
horizontal jitter
Low volume, sound
distortion
Tape twisted
No tape run,
slack tape
Cause
Dirt on F/E head
Dirt on video heads
Dirt on video heads (drum),
tape transport system
Dirt on A/C head
Dirt on pressure roller,
capstan belt
Insufficient torque of D37
clutch assembly
Dirt on video heads (drum),
tape transport system
Portions to be checked
Clean part of F/E head where
tape is in contact
Clean video heads
Clean video heads (drum) and
tape transport system.
Clean part of A/C head where
tape is in contact
Clean pressure roller and capstan
shaft. Check capstan belt.
Check torque of D37 clutch
assembly
Clean and check tape transport
system.
Component
replacement
Component
(a)
(b)
(b)
(c)
(d)
(e)
(f)
(a)
(b)
(c)
(d)
(e)
(f)
Fig. 5-4-2 Locations of Components to Be Checked