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 of Table 8-1.
(2) Step to the specified track.
(3) Connect a frequency counter to the INDEX signal: TP7
(4) Check that the freguency counter readings meet the specifications of Table 8-1.
9.2 Write Protect Verification
(1) Check that the exerciser's write protect lamp goes on and off as a diskette is inserted and
removed as specified in the table below.
Diskette with write protect Diskette with write protect
hole open hole closed
(Not write protected) (write protected)
9.3 Head Output Verification
Use a new diskette if possible to identify head failure for this check.
(1) Insert a good diskette.
(2) Runthe motor.
(3) Stepto the track specified in the output level column of Table 8-1.
(4) Connect the oscilloscope probe as specified below.
Invert channel 2 and select the Add mode.
Set vertical deflection to 10 mV/division and horizontal deflection to 20 ms/division.
(5) Write 2F (all "1"s) on the entire circumference.
(6) Check that the average output level meets the specifications of Table 8-1.
_ Vmax + Vmin
Vaverage =
If it does not meet the specifications, refer to Item 7 of the Trouble Analysis Table.