AMSTRAD CPC664 - Page 12

The data contained
in the following 4
pages
is for
information only. Service
Agents
must not carry
out any repair or
adjustment to the Drive mechanism
and its associated
PCB 30001
during
warranty. Faulty
mechanism
must be
returned to AMSTRAD for
exchange.
Alignment Checks
Please
use
this this information
in conjunction
with the
diagnostic flow
chart.
Equipment required: Double Beam Scope;
EME
-
CF2
Test Disk (please
refer
to
disk notes for usage).
The following checks can be
carried out
in routine
servicing. If the wave
patterns do not
appear
this
confirms
a
fault with the
mechanism.
Before
attempting any
replacement check these
waveforms
thoroughly.
Content of
adjustment and
checking
CE
DISK
EMECF2
1
.
Redial
adjustment
by
use of
Track 1
9
(Fig.
1
).
2. Adjustment
of the index burst by use
of Track 39
(Fig.
2).
3.
Azimuth check by use
of Track 39
(Fig.
3-4).
O
o
o
List of Test
Points
Test
point
Name of signal
TP 1 Read
signal of
filter outlet
TP2 Read
signal of filter
outlet
TP3
Signal ground
TP5
TROO sensor output
TP9
Index signal
TP
11 Signal ground
2ms 2ms
»«
•
n0.5
ms
2F IF
BLOCK 2
BLOCK
3
i
1
BLOCK
49
i
1
IF
300us
500us
-+U+-
r
500us
-ii-
200ms
(TOTAL 49 BLOCKS)
INDEX
INDEX
Fig.l
Waveform of T19 (Servo pattern)
12