Service manual
i\1Z SOK
•
Trouble
Shooting Chart
Problem 1:
No picture appears.
No
picture
1
N~
N°rl
Check
for
Check
for
CPU board.
CPU board.
Only
Check
for
Check
for
VR·
Y Check
for
1-
..
raster
I-----
video
Check
for
R2002,
02001
and
+12V
power
appears.
input
signal.
OkL.
video
vide0-40V
power
,
supply.
circuit.
supply.
~
Ok
Neither
L.
raster
nor
picture
No
appears.
r1
Check
for
CRT
plug.
Check
for
middle/
Ok
.....
high voltage
IJ
-1
CRT
in
trouble.
rectification
4 Check
for
Ok
(02006,
02009
and
CRT
~.
CRT
in
trouble.
FBT.I
heater.
L-
Ok
Check
for
high
'-
voltage
at
K,
f--
Check
for
AFC,
G1,
G2
and
~
Check
for
~~
horizontal
G3
of
CRT.
No
FBT
circuit.
oscillator and
No
drive
output
circuit.
Problem 2:
Sync operation remains ineffective.
NH
Check
for
CPU
/
Neither
Check
for
sync.
board.
r-"
horizontal
nor
separation
(02001
vertical sync.
and
020021.
operation
is
Is there
r--
ineffective.
sync.
Check
for
integrating
signal?
Only
vertical
circuit
(R2012,
R2013,
Ok
sync.
operation
and
C2006
to
C2oo8).
is
ineffective.
Only
horizontal
Check
for
AFT
circuit
L-.,
sync.
operation
(Check
point
(j)
output
of
is
ineffective.
FBT,
R2026,
C2018
and
R20271.
Problem 3:
Raster
is
too
narrow.
N~
Check
for
V-HOLO
VR,
C2OO9
and
R2014.
Is
vertical oscil-
Check
for
I
latior
waveform
I--
No
R2018
and
normal (at
pin
@)
C2012.
NO~
12001 defective I
of
ICI2001)?
Is
input
waveform
I
Ok
of
12001 (at
pin
1-
(2))
normal?
Is
output
Ok
waveform
of
-
Check
for
deflec-
12001 normal?
Ok
tion
coil
(C20161.
Problem 4: No sound comes
out.
Nr---{
Again set
./
correct
program.
No
I
Check
for
CPU
Is
program
r-
board.
correct?
N<:....
Check
for
VR,
r-{
Is there
1--
R2046
and
Ok
audio
signal?
Is
input
C2038.
Nri
l
2002
defective l
signal
of
O~
12002 (at
f---
pin@)
normal?
Is
output
I
signal
of
12002
Ot-'
(at
pin(1))
~
Check
for
C2045
and 1
Ok
speaker.
normal?
-18-