Sanyo PLC-EF31 Service Manual page 24

* NO POWER-2
Check the switching regulator.
STR-Z2156
Switching regulator
Caution : "HOT" Circuit !
If a temperature of this
frame reaches to 150˚C,
the IC632 will be shut
down.
IC632
7
11
Timing chart
Pin 4
OSC OUT
Pin 2
Pin 10
Troubleshooting
If this Vcc voltage reaches to
abnormal voltage (exceeds
22V), the IC632 will be shut
down.
Vcc
8
PROTECTION
ABNORMAL
ABNORMAL
START
TEMP. DET.
VOL. DET.
DELAY LATCH REF
OSC
OC-RC OSC
CONTROL
6 5
CONT
CHECK !
Check the signal at pin 5
of T621. (Switching power
IC output signal.)
G (H)
9 15 2
1
FET
14
LOGIC
FET
12
4 10
G (L)
VOLTAGE CONTROL
ABNORMAL VOLTAGE DETECT
-24-
T621
D655
Vin
D651
OUT
5
D652
6 1
5 2
PC611
4 3
6 1
PC612
5 2
4 3
If this voltage reaches to
abnormal voltage (exceeds
6.8V), the IC632 will be shut
down.
9V
16V
6.25V
-6V
3 3
2
2
IC652
1
1
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