Description; Head Cleaning; Adjustment Procedure - Commodore 1540 Technical Manual

3.7
Description
Periodic maintenance is indispensable so
peripherial equipment operates properly,
important to periodically clean the head and
Repairs and adjustments should be made in
proceedures below.
that this type of
It is particularly
check the load pad.
accordance with the
3.8 Head Cleaning
Check for excessive dust or magnetic oxide on the load pad. With
the door open (do not move upper arm greater that what, is provided
by opening the front door) clean head with lint free cotton cloth
or !Q-tip' in 91/ isopropyl alcohol. Wipe the head carefully to
remove any dust and/or oxide.
3.9 Adjustment Procedure
In case of a malfuction or parts replacement, make the following
adjustments. In order to maintain the interchangability of the
media between drives it is desirable check each drive against a
master alignment diskette.
3.9.1 Track adjustment (radial track)
a) Connect I/O cable an restore the head to track 00.
b) Insert a 48tpi alignment diskette and close the door.
c) Connect two oscilloscope probes to pin 1 and pin 14 of UH6
(592), set oscilloscope to angbraic add at 50mV/cm and 200
msec/div.
d) Load the head and allow it to seek to track 16, check for cats
eye wave form. When the cats eye lobe ratio is 70/ or less,
loosen the stepping motor mounting screws, turn the stepping
motor to obtain the lobe ratio of 90/ or less.
e) After allowing the head to track 34, return it to track 16 and
recheck the cats eye. If the ratio is correct tighten the
stepping motor screws.
4
X i o o ^ 1 0
Cats eye lobe ratio
19