Resolution Check; Symmetry Check; Write Protect Sensor Check; Head Cleaning - AMSTRAD PC1512 Service Manual

5-7
Resolution
Check
a)
Insert
a blank
diskette.
b)
Move
the head
to
Track
39, write
1
F
and 2F
by the top
and bottom heads, then
measure
the
average
output
level.
c)
The
resolution
is
higher than
55%, and
calculations
shall
be
as follows:
2F
output (mV)/1 F output (mV)
x
1
00>55%
Measuring
Conditions
Channel
1-TP1 (10mV/div)
MODE-ADD
Channel 2-TP2
(10mV/div) Sweep-20ms/div
Trigger—
TP6
2F average
output
level
Resolution
=
1
F average output
level
95%
or less with
TKO
55%
or
more
with
TK39
5-8
Symmetry Check
a)
Insert
a blank
diskette.
b)
Move
the
head
to track
and
write
1
F by the top
and bottom
heads.
Measuring
Conditions
Channel
1-TP5
(0.1V/div)
MODE--CH1
Trigger— INT.CH1
Sweep-0.5ms/div
Slope(+)
T
=
400
ns
or less
(If
you have
individual spec,
this
item
obey your
spec.)
5-9
Write Protect
Sensor Check
Load and
unload a diskette
and check
that write protect
sensing
is
definitely
made
using Brikon.
5-10 Head
Cleaning
Check
for
excessive dust
or oxidised
magnetic
iron
powders on
the load
pad
using
such a
dentist's
mirror.
Clean the
heads
using
a
cloth that
produces no
flues or
an
applicator
dipped
in
91%
isopropyl alcohol.
Clean
the
heads
carefully
and remove accumulated
dust
and
oxidised
magnetic
iron
powders.
Wipe
the head
using a cloth that
produces no
flues.
14