Main C.B.A.
Figure 2
3. Turn on SW1 and then turn on the set. Confirm that the picture is
on the screen properly.
4. Confirm that the picture goes out of horizontal sync while getting
down by varying VR.
5. If this does not occur, it means that X-ray protect circuit is not
operating. Further confirmation and repair is required.
2.2. REPAIR PROCEDURES OF HORIZONTAL OSCILLATOR
DISABLE CIRCUIT
1. Connect a DC voltmeter between capacitor C513 (+) on the Main
circuit board and chassis ground.
2. If approxi23.0 V (For model with 20 inch CRT), +21.5 V
(For model with 27 inch CRT) is not present at that point when 120
V AC is applied, find the cause. Check R508, R503, R5505, C5507,
C513 and D503.
3. Carefully check above specified parts and related circuits and
parts. When the circuit is repaired, try the horizontal oscillator
disable circuit test again.
2.3. CIRCUIT EXPLANATION
2.3.1. HORIZONTAL OSCILLATOR DISABLE CIRCUIT
The positive DC voltage, supplied from the D503 cathode for monitoring high voltage, is applied
to the IC5301 Pin 11 through R508 and R5504. Under normal conditions, the voltage at IC5301 Pin
11 is less than approx. 6 V. If the high voltage at FlybackTransformer Pin 5 exceeds the specified
voltage, the positive DC voltage which is supplied from the D503 cathode also increases. The
increased voltage is applied to IC5301 Pin 11 through R503 and R5504. Due to the increased
voltage at IC5301 Pin 11,the horizontal oscillator frequency increases, the picture goes out of
horizontal sync, the beam current decreases and the picture become dark in order to keep X-
radiation under specification.
Figure 3
6
Summary of Contents for PV 20DF63
Page 1: ...ORDER NO MKE0303602C1 B6 B22 TV DVD Combination PV 20DF63 PV 27DF63 SPECIFICATIONS 1 ...
Page 15: ...5 1 8 WIRE AND LEAD POSITION DIAGRAM Fig 8 15 ...
Page 18: ...Fig D2 18 ...
Page 19: ...Fig D3 19 ...
Page 20: ...6 1 1 1 Notes in chart 1 Removal of DVD Ass y Fig D4 20 ...
Page 38: ...7 3 TEST POINTS AND CONTROL LOCATION 38 ...
Page 41: ...11 2 CHASSIS FRAME SECTION 2 41 ...
Page 42: ...11 3 CHASSIS FRAME SECTION 3 42 ...
Page 43: ...11 4 PACKING PARTS AND ACCESSORIES SECTION 43 ...
Page 54: ...R6012 ERJ6GEYJ561V MGF CHIP 1 10W 560 54 ...
Page 90: ...13 2 CHASSIS FRAME SECTION 2 90 ...
Page 91: ...13 3 CHASSIS FRAME SECTION 3 91 ...
Page 92: ...13 4 PACKING PARTS AND ACCESSORIES SECTION 92 ...