Sony WALKMAN WMD-DT1 - Mechanical Adjustments; Adjustment Precautions and Torque Check; Tape Path Adjustment Procedure

SECTION 4
MECHANICAL ADJUSTMENTS
Precautions
1. Input a DC 3.0V power supply to the DC IN 3V jack.
To clean the drum, moisten a chamois leather (2-034-697-00) or
cloth (knit) that has been folded into fours with alcohol slightly,
press it lightly against the drum and rotate the drum in the
counterclockwise direction (2 to 3 times).
Torque Check
TW-7131 3.5 to 5.5g*cm
(8-909-708-71) (S side)
REVIEW (44 = D> + 44)
back Tension
TW-7131
(8-909-708-71)
0.5 to 1.5g*¢cm
(T side)
Tape Path Adjustment
Be sure to perform this adjustment when.the drum, S side roller guide
section parts and T side roller guide section parts are replaced.
Procedure:
1. Remove the. cassette lid assembly and case assembly.
2. Connect CH1 of an oscilloscope to TP80 (RF) and TP79 (RF GND)
of the main board, then CH2 (trigger) to TP78 (SWP).
—
Main
board
(side
A)
—
TP79
(RF
GND)
TP8O (RF)
TP78 (SWP)
3. Load the test tape TY-7231 (8-119-874-00) and press PLAY (P>).
4, Check that the waveform of the oscilloscope (RF signal) becomes
®,®.©.0,
©,
®,
or
©
shown
in
Fig.
1
(There
must
be
two
peaks
or less
and
the
marginal
area
must
appear
as well.).
If the specification is not satisfied, perform adjustments from step 5.
If the specification is satisfied, perform adjustments from step 7.
Marginal area
Marginal area
0 peak
0.5 peak
1 peak
1 peak
1.5 peaks
2 peaks
2 peaks
© There must be two peaks or less and the marginal area must appear
as well,
« Approximate upper waveform value: 0.4 to 0.6 mV when the waveform
is most spread.
Fig. 1.