Philips VR705/02 - Page 69

After replacing the roller unit (right), the tape path has to be
checked, and adjusted if necessary (paragraph 4.2.1).
4.1.9 Roller unit left (Pos.23)
Set the drive assy to ,Eject’ position.
Unhook the tension arm spring (pos. 11), to avoid the tension arm
spring being pre-loaded.
At the bottom side of the drive assy remove the tension lever
(pos.112).
Compress the two snap hooks by means of a pair of tweezers
(Fig. 9)and remove the roller assy (A) from the plate (B).
Unhinge the loading arm (left) from the holding plate and remove
the latter downward from the drive assy through the recess in the
chassis (Fig. 15).
The reassembly is carried out in reverse order.
NOTE : During reassembly
1. Place the carriage holding plate in the assembly with the half-
round cutout nearest the rear of the deck.
2. When the loading arm is refitted ensure the pin on the underside
of 23 is through the link of 24B.
After
replacing
the
roller
unit
(left)
the
tape
path
has
to
be
checked
(paragraph
4.2.1.),
and
adjusted
if
necessary.
fig. 15
4.2 Adjustments
Adjustments must not be made in the service position.
4.2.1 Tape path
4.2.1.1 Roller left unit/roller unit right
Preparation:
Connect one input of a duai trace oscilloscope to observe the tape
sync pulse CTL. The other input (DC coupled) to observe the
tracking information TRIV.
Trigger the oscilloscope externally on the head pulse HP1
(“SWIN’).
4-5
Playback the black and white section of the alignment test tape.
Set the deck in the condition where the video heads are running
along the upper edge of the tracks only by:
1. Call the service test program (chapter 2.1)
2. Activate manual tracking (service test program step 03) and
watch the tape sync pulse move to the left in relation to the TRIV
signal.
3. Note the extreme left hand position reached by the sync pulse,
repeat as necessary.
4. Stop the movement of the pulse when the TRIV signal reduces
to 1/2 to 2/3 maximum amplitude by pressing the normal play
button. A noisy picture (disturbances) is visible on the TV set and
the CTL pulse should be to the left of the display.
The recorder will hold this position until the service test progam
step 03 is left.
This condition works only if X-distance is adjusted.
Picture is visible
trom toil side
fig. 18
Adjustment:
Adjust the left and right roller units to make the tracking signal TRIV
straight and flat as possible (Fig. 18).
4.2.1.2 AIC Combi head
Tilt angle adjustment
Set the drive to feature mode (e.g. +7)
Adjustment :
Tape guide
Capstan wheel
(2) rane guide
(Reverse lever)
Pressure roller
GB