Sharp FDD-412A - Page 90

FDD412A/B
— oe
ee :
Set shorting-
plugs to
specify normal
operation
mode.
FDC error is
suspected. -
A-A
See 5.2 ''Media-
Related Troubles"
for trouble-
shooting.
i
' NO
ae
HEAD ENGAGE-N: (1C16-17)
STEP-N (TP-8)
|
oe
ae
Read
output
(TP1/2)
|
Re
ee
ee
WRITE
GATE-N
(1024-5)
|
oe
ers
LOW
CURRENT-N:
(IC27-1)
|__NO_ovér
VFO
SYNC,
DATA
GeO.
SENCER
(1027-9)
ne
er
cee
DATA
AREA-N
(1C27-5)
a
[MEM
GATE-N
(1027-11)
YES
=}
ower supply NO
oltages normal?
+5V (J2-3)
TES 494y (12-1)
Has over-
YES
: voltage damaged
Normal opération : :
NO = circuit?
ode specified wit
shorting-plugs?
NO
Apply normal
line voltage.
Replace
damaged
circuit.
YES
Head loaded on? MY
Wait~time normal
a“ ™~
after HEAD ENGAGE OF
STEP pulse?
YES
NO EAD ENGAG
signal input?
NO Spindle motor
revolutions normal?
Head load NO
FE
AES olenoid |
a ie
YES Réad waveshape YES
(envelope) normal?
NO
Replace head
load solenoid.
solyf J
Read operation
NO performed during~
within 580 us of
WRITE GATE?
YES
Or.
_
_— ;
Replace PWB Asse
l
LOW CURRENT
N
- signal control
normal?
“SS
Fig.
5.7
Read
Error
(2)