Sharp 55R-WP5H, Service Manual

Page: 23 / 112

23
61R-WP5H
55R-WP5H
3. Self-diagnostic Function (Protector Circuit Operation)
This model is equipped with five protector circuits. Shown below are the detections of the protector circuits and
possible trouble spots (outlined).
Micro-processor
52
1
36
64
IC501
6
4 7
3
3
1
5
Switching P
o
w
e
r Ov
er-v
oltage Protector Circuit
A:
∫
+10V
, +25V
, 32V and -25V line v
o
ltage r
ise detected
B:
∫
Switching po
w
e
r pr
imar
y-side circuit in troub
le
(causing v
o
ltage r
ise)
∫
Chopper regur
ator malfunctioning
(DUNTKA233WE)
Deflection UNIT
(DUNTKA232WE)
Signal UNIT
FBT
+10V line
+130V line
-8V line
+25V(CONV) line
-25V(CONV) line
32V(S) line
-14V line
+14V line
T630
Detection Circuit
Current AMP
Dr
iv
e
Q652
D693
D6502
D6504 Q9980
Q639
Q3503
Dr
iv
e
Dr
iv
e
Rela
y
Dr
iv
e
Q3501 Q3507
IC3501
Hor
iz
ontal
Protector
V
e
rtical Protector
Stand-b
y
ON/OFF
(Rela
y
SW)
P
o
w
e
r Protector
Q3618
5V
6.5V
Q1704
Q1702
A
C
Rela
y
(DUNTKA235WE) Sub P
o
w
e
r UNIT
D9924
D9986
D9981 D9980
D9984 D9987
D9985
D9989 D9922
D9983
Q9981
D9996
D9995
D9993
D9994
Dr
iv
e Circuit
(DUNTKA234WE)
P
o
w
e
r UNIT
Dr
iv
e Circuit
1
Ov
er-Current Protector Circuit
A:
+130V line current detected (Flybac
k tr
ansf
or
mer r
ush current detected)
B:
∫
Flybac
k tr
ansf
or
mer detectiv
e
.
∫
Hor
iz
ontal deflection circuit tr
ansf
or
mer or diode
shor
t-circuited
∫
Flybac
k tr
ansf
or
mer secondar
y-side rectifier circuit
par
ts shor
t-circuited or load circuit par
ts shor
t-circuited
2
X-Ra
y Rdiation Protector Circuit
A:
Flybac
k tr
ansf
or
mer ter
m
inal
3
v
o
ltage detected
B:
∫
Resonance capacitor open
∫
Hor
iz
ontal circuit open
3
V
e
rtical Output Protector Circuit
A:
V
e
rtical output (pulse) monitored and no-pulse
condition detected
B:
+14V line circuit in troub
le
, causing v
o
ltage drop
(rectifier circuit par
ts shor
t-circuited) or circuit open
4
Switching P
o
w
e
r Secondar
y-side under-v
oltage
protector circuit
A:
∫
+10V
, +25V
, 32V
, -8V and -25V line v
o
tage detected
B:
∫
+B line rectifier circuit par
ts (diode
, capacitor) shor
t-circuited
∫
+B line load shor
t-circuited
A:
Detection
B:
P
ossib
le
T
roub
le Spot