AOC TREINAMENTO LCD TV-MONITOR _ BOARDS AND SCHEMATICS

POWER SUPPLY BOARD

POWER SUPPLY - SCHEMATIC

INVERTER BOARD - SCHEMATIC

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OPERATING CHARACTERISTIC [INVERTER BOARD]

• When START is given on TV, the logic board via the PS sends 5V on pin 11 to ON CN902 connector with high level at the base Q934 he is so saturated with current flowing in IC934 with photo coupler activated resistance between the transistor collector and emitter decreases, thus having a voltage in the zener diode ZD933 stabilized reference point B. with the B at a high level at the base saturating the transistor Q932 have then the VCC voltage of 13.8 V.
• Through the resistor R 907 is injected at pin 8 a voltage 160V feeding the IC 901 at initial time (start) and makes Induction that the transformer (T901) pin 2 is 13Vcc generated voltage after rectification to the pin 926 in D 1 of IC 901 (Vcc).

Pins 2 and 5 are Earth's IC.

Pin 3 CT / RT (IC oscillator)

• Pin 4 is applied to a sample voltage (1.3 V) serves as a reference for stabilization of the pulse width PWM output pin 7 of IC 901. When the current exceeds its limit, voltage drop occurs over  920 (0.11 V) reflected on pin 6 (limiter) of IC 901, making with the IC901 remove the output pulse at pin 7, taking FET to cut off the source.
• When the current exceeds its limit, voltage drop occurs over the pin 5 Isen (1.2 V) of the U making 811 with the IC remove the pulse output pins 1 and 15 leading FET's (Q 821 and Q 841) to the court, turning off the backlights to protect the inverter circuit
• When there is an increase of voltage on pin 6 Vsen (above 2.1 V) due to U 811 D 853 and D 833 reflect the extra high voltage transformers coming EN 801 and EN 802 is removed from the output pulse on pin 1 and 15, the FET's leading Q 821 and Q 841 to cut off the backlights for protection inverter circuit

With TV is off working only the power circuit board 5 volt logic.  That circuit is built around IC931.[Standby voltage circuit]

MAIN DIGITAL BOARD