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Safety Precautions
1. It is safe to adjust after using insulating transformer
between the power supply line and chassis input to prevent
the risk of electric shock and protect the instrument.
2. Never disconnect leads while the TV receiver is on.
3. Don't short any portion of circuits while power is on.
4. Don't operate the TV with a non-moving picture for any
more than 10 minutes as damage may occur to the phosphor
on the CRT.
5. The adjustment must be done by the appropriate appliances
and the correct step.
6. Unless otherwise noted, set the line voltage to 220V ± 10%,
50Hz.
T est Equipment required
1. VIF sweep generator
2. Color bar/cross-hatch pattern generator
3. DC power supply
4. Digital multi-meter
5. Color analyzer
Preparation for VCO & AFT Adjustment
1.
Connect the measuring equipment to the TV as shown in
Fig.1.
2. Set RF output level of Sweep S.G (Signal Generator) to
80dBuV.
3. Set Alignment Scope, Volts/Div to 100mV (VCO) or
1V(AFT), AC/DC switch to AC, Line/Ext switch to Ext.
IF Board (Component side view)
IC1S
P103B
PIP Board (Component side view)
P502B
P2B
P2B
TU2P
NOTE: TP point is on the copper side of PCB.
ADJUSTMENT INSTRUCTIONS
TP6
VR1T
AGC
L9T
VCO
IC1T
TP5
TP1
TP2
L8T
TP3
AFT
TP4
P102B
P101B
IC2P
L8P
VCO
L9P
AFT
TP22
IC1P
TP25
TP23
TP24
TP21
TP20
VR1P
AGC
J21P
AGC TP
DC POWER
SUPPLY
+ -
12 0.1V
SWEEP S.G.
with Marker
(VP-8800G)
Alignment
Scope
Fig.1 : Connection Diagram of Equipment for
VCO & AFT Adjustment.
NOTE :
: PIP Board
● VCO (Voltage Controlled Oscillator)
Adjustment
Test Point :
Adjust :
1) Turn on DC power supply.
2) Adjust Video Detector Coil (L9T/ L8P ) so that a waveform
on Alignment Scope is the same as below Fig.2.
A
B
C
Fig.2 : VCO waveform on Alignment Scope
● AFT (Auto Fine Tuning) Adjustment
Test Point :
Adjust :
1) Turn on DC power supply.
2) Adjust IF AFT coil (L8T/ L9P ) so that 38.0MHz (Vc) point
may be centered as Fig.3.
- 16 -
To TP2/ TP21
3.3K
To TP5/ TP24
1K
4.7K
VCO : ON
AFT : OFF
0.01µF
To TP1/ TP20
(VCO)
To TP6/ TP22
(AFT)
To Pin5 of P101B
/ Pin7 of P1B
TP6 / TP22
L9T / L8P
D
E F
G
PIN5 of P101B / PIN7 of P1B
L8T / L9P
A : 30.0MHz
B : 31.5MHz
C : 32.84MHz
D : 36.8MHz
E : 38.0MHz
F : 39.5MHz
G : 40.25MHz
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