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2.2.3.7 SCREEN & FOCUS SHORT CIRCUIT PROTECTION
Above circuit is used for protection against screen & focus grounding. Basicly the base
of PNP transistor Q609 is connected to screen&focus potentiometer of FBT, in another words
FBT focus pack is connected to ground via R654. The voltage at the base of that transistor is
normally higher then the zener voltage at the emitter. When any short circuit occurs at focus
or screen the base voltage is decreased to a value lower then zener voltage, that forces
transistor to conduction and trigers another circuit which will force UC to protection mode. In
protection mode LED becomes RED and remote control does not work.
Summary of Contents for 28YT56
Page 1: ...SERVICE MANUAL PRINTED IN UK 2003 C COLOURTELEVISION 28YT56 32YT56 TOSHIBA ...
Page 7: ...6 Block diagram of the TV System with face down version is ...
Page 8: ...7 ...
Page 22: ...21 ...
Page 33: ...32 Pin NO Signal 1 14 volt 2 80 volt 3 EHTINFO 4 HEATER 5 GND 6 7 200 volt ...
Page 34: ...33 2 2 6 CABLE SPECs 2 2 6 1 RGB CABLE ...
Page 35: ...34 ...
Page 36: ...35 2 2 6 2 200V CABLE with BSVM ...
Page 37: ...36 ...
Page 38: ...37 2 2 6 3 200V CABLE without BSWM ...
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Page 76: ...75 6 PICTURE MODES ...
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Page 80: ...79 7 CIRCUIT DIAGRAMS ...
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