Adjustments And Verifications; Motor Speed Verification (Index Period); Write Protect Verification; Head Output Verification - Panasonic JU-475-4 Service Manual

9. ADJUSTMENTS AND VERIFICATIONS

9.1

Motor Speed Verification (Index Period)

(1) Insert a diskette, run the motor, and clamp. Refer to the index period column o f Table 8-1.
(2) Step to the specified track.
(3) Connect a frequency counter to the INDEX signal:
(4) Check th a t the frequency counter readings meet the specifications o f Table 8-1.
9.2

Write Protect Verification

(1) Check th a t the exerciser's w rite protect lamp goes on and o ff as a diskette is inserted and
removed as specified in the table below.
Diskette w ith w rite protect
hole open
OFF
(Not w rite protected)
9.3

Head Output Verification

Use a new diskette if possible to identify head failure fo r this check.
(1) Insert a good diskette.
(2) Run the motor.
(3) Step to the track specified in the o u tp u t level column o f Table 8-1.
(4) Connect the oscilloscope probe as specified below.
CHI CH2
TP1 TP2
Invert channel 2 and select the Add mode.
Set vertical deflection to 10 mV/division and horizontal deflection to 20 ms/division.
(5) W rite 2F (all " 1 "s) on the entire circumference.
(6) Check th a t the average o utput level meets the specifications o f Table 8-1.
w _ Vmax + Vmin
v average ~
If it does not meet the specifications, refer to Item 7 of the Trouble Analysis Table.
Diskette w ith w rite protect
hole closed
( w rite protected)
EXT
TP7
2
- 7 -
TP7
ON