Sanyo CE21KF8R, Руководство по обслуживанию

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Service Information
This TV set has a built-in power supply protection circuit.
It is provided to protect the TV set in case of a power supply circuit malfunctions. When something abnormality
occurs during TV reception, the TV set goes to the stand-by mode.
When an abnormality occurs during TV reception, it causes pin 27 of the CPU to go continually Low for about
one second. The CPU detects that this has occurred and outputs the signal from pin 31 to switch off the power
supply lines.
Releasing the protective circuit and restoring power supply
To release the protective circuit and restore power supply, turn the power to the TV set OFF and then ON again
via either the main power switch or the ON-OFF button on the remote control. This will work only if the power
supply trouble was temporary. If there is permanent trouble such as a damaged circuit, power cannot be
restored and the circuit will have to be repaired.
Protection Circuit
IC3701 < Audio Control & Surround > NJW1142M
6
8
1
7
20
10
25
22
NJRC
ORIGINAL
SURROUND
&
SIMULATED
STEREO
IIC BUS
INTERFACE
AGC
BIAS
TONE
VOL 1
TONE
VOL 1
VOL 2
VOL 2
19
18
14
13
16
15
17
30
21 23
24
12
11
IN 1a
AGC
TONE Ha TONE La
OUT a
CVa
CVb
CTH
CTL
CSR
SCL
SDA
V+
GND
VREF
OUT b
SR-FIL
TONE Hb TONE Lb
5
MONa
-2dB
SEL
2
IN 2a
3 IN 3a
4 IN 4a
IN 1b
SEL
IN 2b
IN 3b
IN 4b
29
28
27
MONb
-2dB
26
9
+4.5 dB
LINEa
LINEb
+4.5 dB
IC Block Diagrams
14
13
Pulse
DET
Pulse
I/F
Clamp
VCO
SW2
15
Filter
PLL
DET
16
17
System
SW1
LIM KILLER
Bell/EQU
Filter
SW3
18 19
ACC
Bell/EQU
Adj
20
1 2 3
ID-KIL
ID
4
5
F0 Adj
6
7
SW/ALC
8
F0-Fil Kil-Fil
4.43DC ID-Fil
4M-DC
R-Y Out
B-Y Out N.C.
4MHz In SC-In
4.43MHz In AV/SECAM
Kil-Out
Video In
Vcc EQU-Adj
9 10
GND
11
12
N.C.
N.C.
N.C.
IC281 < Secam Decoder > LA7642NM-TLM-E
SM_21-C5GSH (Rus) 6/28/04 11:33 AM Page 8