13
Model No: CT-21FDS1
Version 1.0
FAULT FINDING TREES, DIAGRAMS AND OVERVIEWS
1. Three-None (no raster, no picture, no sound)
This failure is mainly caused by big-power circuit such as power supply, horizontal scanning, vertical scanning.
The detail checking and repairing steps are as follow.
0V
4.5-5.5V
YES
0V
1V
0.6V
300V
NO
YES
0V
300V
0V
0V
115V
No variation
Norma
115V
0V
Others
24V
2V
9V
115V
LOW
NO
variation
50V
Test the voltage of C563
Cut off W560
T
T
Te
e
es
s
st
t
t
o
o
ot
t
th
h
he
e
er
r
r
v
v
vo
o
ol
l
lt
t
ta
a
ag
g
ge
e
e
s
s
su
u
uc
c
ch
h
h
a
a
as
s
s
1
1
18
8
88
8
8V
V
V,
,
,
2
2
24
4
4V
V
V,
,
,
a
a
an
n
nd
d
d
V551,VD551,RP551,V552,
VD517,V572,V511
Check VD556,C563
Recover W560, unplug
XZ411 for a While,then
test the voltage of C563
Check V411,T402,T401,
Deflection coil
Check L414,VD403,C411
Deflection coil
Voltage of C507
Check if V501 collect-emitter
Was broken down
Check R502,F501,power
Swich, AC cord and plug
Check the voltage
of V501 collector
Check V501,V512,F501,R502,VD503
Check T501
Test voltage of V501 base
Check
T501,VD517,
C515,C517,V411,
VD552-VD555
C415,C416,T402
C412
Check if it get right
When cut off V572
Test the voltage of
D901 pin7
CPU has sent the
Power-off signal
Check if V572
is broken down
Check V501
Check
R552,V551,VD551
VD515,V511,
V512,R555
N201 pin8 voltage
N201 pin32 voltage
Check Z901,C901,
C902,N204
V444 pin C voltage
Check
VD553,C559,
]R437,C430,T401,
C415,V411
Check R320,V444
Check T402
Check V411 pin C voltage
Check T402,V411,R449
Others
115V
0V
