§
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.
§
Test Equipment required
1. VIF sweep generator
2. Color bar/cross-hatch pattern generator
3. DC power supply
4. Digital multi-meter
5. Color analyzer
NOTE :
: PIP Board
¡
Main VCO (Voltage Controlled Oscillator)
Adjustment
1) Turn on DC power supply.
2) Adjust LI6 so that the waveform of Oscilloscope becomes
2.6V DC.
¡
PIP VCO (Voltage Controlled Oscillator)
Adjustment
1) Turn on DC power supply.
2) Adjust Video Detector Coil ( LP8 ) so that a waveform on
Alignment Scope is the same as below Fig.2.
¡
AFT (Auto Fine Tuning) Adjustment
1) Turn on DC power supply.
2) Adjust IF AFT coil (LP5 ) so that 38.0MHz (Vc) point may
be centered as Fig.3.
Test Point :
TP22
Adjust :
LP8
ADJUSTMENT INSTRUCTIONS
Test Point :
TP3
Adjust :
LI6
- 14 -
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
90dBuV.
3. Set Alignment Scope, Volts/Div to 100mV (VCO) or
1V(AFT), AC/DC switch to AC, Line/Ext switch to Ext.
DC POWER
SUPPLY
12 0.1V
SWEEP S.G.
with Marker
(VP-8800G)
Alignment
Scope
+-
To TP2/ TP21
To TP1/ TP20
To TP3/ TP22
TP23
TP24
VCO : ON
AFT : OFF
3.3K
1K
4.7K
0.01
µ
F
(VCO)
(AFT)
Fig.1 : Connection Diagram of Equipment for
VCO & AFT Adjustment.
2.6V
GND
A
B
C
D
E F
G
A : 30.0MHz
B : 31.5MHz
C : 32.84MHz
D : 36.8MHz
E : 38.0MHz
F : 39.5MHz
G : 40.25MHz
Fig.2 : VCO waveform on Alignment Scope
Test Point :
TP23
Adjust :
LP5
A
B
A: 36.8MHz
B: 38.0MHz
Fig.3: AFT waveform on Alignment Scope
Содержание PF-43A20
Страница 11: ... 11 ALIGNMENT TEST POINT LOCATION GUIDE SIGNAL Board Component side ...
Страница 12: ...DEFLECTION Board Component side 12 ...
Страница 13: ...IF Component side 13 PIP Component side CPT Board Component side VR902R VR902G VR902B ...
Страница 27: ... 27 ...
Страница 28: ... 28 ...
Страница 29: ... 29 ...
Страница 30: ... 30 ...
Страница 32: ... 32 IF MPX PIP ...
Страница 33: ... 33 AV DCF A V 2 ...
Страница 37: ...MEMO 37 ...
Страница 55: ...VIDEO Y C AUDIO ...
Страница 56: ......
Страница 57: ......
Страница 58: ......
Страница 59: ...Oct 1998 P NO 3828VD0053C Printed in Korea ...