•
Set is dead, and makes no sound
Check power supply IC 7520. Result: voltage at pins 1,3, 4, 5 and 6 are about 180 V
and pin 8 is 0 V. The reason why the voltage on these pins is so high is because the
output driver (pin6) has an open load. That is why MOSFET 7521 is not able to
switch. Reason: feedback resistor 3523 is defective.
Caution
: Be careful measuring
the gate of 7521; circuitry is very high ohmic and can easily be damaged!
•
Set is in hiccup mode and shuts down after 8 seconds
Blinking LED (set is in
SDAM mode) indicates error 5. As it is unlikely that P "POR" and "+8V
protection" happen at the same time, measure the"+8V" supply. If this voltage is
missing, check transistor7480.
•
Set is in non-stop hiccup mode
Set is in over-current mode; check the secondary sensing (optocoupler 7515) and the
"Main Power Supply" voltage. Signal "Stdby_con" must be logic low under normal
operation conditions and goes to high (3.3 V) under standby and fault conditions.
•
Set turns on, but without picture and sound
The screen shows snow, but OSD and other menus are okay. Blinking LED
procedure indicates error 11, so problem is expected in the tuner (part reference
number 1000). Check presence of supply voltages. "5V" voltages at pin
5 and 7 are okay; "VT_supply" at pin 9 is missing. Conclusion: resistor 3460is
defective.
•
Set turns on, but with a half screen at the bottom. Sound is okay
Blinking LED (set is in SDAM mode) indicates error 3. Check"11V" and
"+50V". If they are okay, problem is expected in the vertical amplifier IC 7471.
Use an oscilloscope to measure the waveform on pin 17 of the UOC. Also
measure the waveform at pin 1 of IC 7471. If the signal there is missing, a
defective resistor R3244 caused the problem.
Содержание 7629
Страница 1: ......
Страница 5: ......
Страница 14: ...AV2 In SVHS Connector Kind Value Symbol 1 gnd v 2 gnd v 3 Y 1 Vpp 75 O j 4 C 0 3 Vpp 75 O j ...
Страница 16: ...Figure ...
Страница 18: ...Figure ...
Страница 20: ...Figure Panel Removal 1 Lift the board out of its bracket after releasing the 2 fixation clamps Figure ...
Страница 48: ...Hardware Alignments Figure Mono Carrier Top View LS ...
Страница 76: ...Power Supply Figure Figure ...
Страница 101: ...T8 7629 ...
Страница 102: ...T8 7629 ...
Страница 103: ...T8 7629 ...
Страница 104: ...T8 7629 ...
Страница 105: ...All Models 7629 PCB Locations ...
Страница 106: ...All Models 7629 Power Supply Diagram A1 ...
Страница 107: ...All Models 7629 Line Deflection Diagram A2 ...
Страница 108: ...All Models 7629 Frame Deflection Diagram A3 ...
Страница 109: ...All Models 7629 Tuner IF Diagram A4 ...
Страница 110: ...All Models 7629 Video IF And Sound IF Diagram A5 ...
Страница 111: ...All Models 7629 Synchronization Diagram A6 ...
Страница 112: ...All Models 7629 Control Diagram A7 ...
Страница 113: ...All Models 7629 Audio Amplifier Diagram A8 ...
Страница 114: ...All Models 7629 BTSC Stereo SAP Decoder Diagram A9 ...
Страница 115: ...All Models 7629 Audio Video Source Switching Diagram A10 ...
Страница 116: ...All Models 7629 BTSC NDBX Stereo Decoder Diagram A11 ...
Страница 117: ...All Models 7629 Front I O Control Headphone Diagram A12 ...
Страница 118: ...All Models 7629 Rear I O Cinch Diagram A13 ...
Страница 119: ...All Models 7629 PIP Interface Diagram A16 ...
Страница 120: ...All Models 7629 CRT Panel Diagram B1 ...
Страница 122: ...USED ONLY IN MODELS 27PS50B321 32PS55S321 32PS61S321 32PS55S331 7629 Side AV and Headphone Panel Diagram E1 ...
Страница 123: ...USED ONLY IN MODELS 27PS60S321 27RF72S325 32PS61S321 7629 PIP Panel Diagram P ...
Страница 125: ...USED ONLY IN MODELS PC0125C321 PC0127C321 7629 EPS Panel Schematic ...
Страница 126: ...USED ONLY IN MODELS PC0125C321 PC0127C321 7629 Card Interface Schematic ...
Страница 127: ...USED ONLY IN MODELS PC0125C321 PC0127C321 PL0125C321 PLW225S321 PRF227S325 7629 SP LS Panel Schematic ...
Страница 128: ...All Models 7629 Main Panel component side ...
Страница 129: ...All Models 7629 Main Panel copper side ...
Страница 130: ...All Models 7629 CRT Panel component side ...
Страница 131: ...All Models 7629 CRT Panel copper side ...
Страница 132: ...All Models 7629 Headphone Panel component side ...
Страница 133: ...All Models 7629 Side AV Panel component side ...
Страница 134: ...All Models 7629 PIP panel component side ...
Страница 135: ...All Models 7629 PIP panel copper side ...
Страница 136: ...All Models 7629 Top Control Panel component side ...
Страница 137: ...All Models 7629 EPS Panel PCB Top View only ...
Страница 138: ...All Models 7629 Card Interface Panel PCB Top View ...
Страница 139: ...All Models 7629 Card Interface Panel PCB Bottom View ...
Страница 140: ...MAIN CABINET EXPLODED VIEW ...