Led Assembly/Index Assembly Check And Adjustment; Index Alignment Waveform - NEC FD1165 Maintenance Manual

a. Insert an alignment flexible disk.
b. Step the carriage to track 01.
c. Load the heads.
d. Observe the timing between the trailing edge of the
index pulse and the first peak of the read waveforms
(see Figure 5-5). It should be 200
f.lS
±
200
J1
s.
e. If the waveform does not meet this specification,
adjust the index sensor as described in Section
4.4.7. If the LED assembly and the index assembly
have been replaced, see Section 5.5.1.
INDEX
PULSE
I :---
1 _ ,
-I
-------- --
200±200JiS
Figure 5-5 Index Alignment Waveform
5.5 OTHER ADJUSTMENTS
The checks and adjustments in this section do not require
the use of the alignment flexible disk.
5.5.1 LED Assembly/Index Assembly Check and Adjustment
If the index sensor and LED assembly are replaced, perform
the following check in addition to the index alignment ad-
justment.
a. When using a single-sided flexible disk, measure
the waveform at TPIO, checking for a pUlse width of
1 to 3 ms (see Figure 5-6).
5-8