Interface Operation - HP WF1907 Service Manual

3. Interface Operation

3.1 Top (Circuit diagrams sheet 2 of 8)
This page is function block. (1) Power. (2) VGA & DDC interface. (3) DVI & DDC interface. (4)
Scaler Gm5726H (Gm5766H). (5) Key & panel interface. (6) Audio.
3.2 Power (Circuit diagrams sheet 3 of 8)
3.2.1 P301 connector
A 5V power supply for LCD module, also it is main power of interface board. A VDD (+5V)
power supply for audio AMP. It is generated from the P301 connector. And adjust back
light of LCD module from I306 sclaer Gm5726H (Gm5766H) control.
3.2.2 I302 : 3-terminal regulator
A 3.3V power supply for I306 scaler IC Gm5726H (Gm5766H) and I308 EEPROM / I309
SPI flash ROM, it is generated from the 5V source.
3.2.3 I303 : 3-terminal regulator
A 1.8V power supply for I306 scaler IC Gm5726H (Gm5766H), it is generated from the
3.3V source (I302).
3.2.4 Q302, I301 : ON/OFF control for LCD module power
ON/OFF control (PANELVCC_EN) is performed for power ON/OFF and also for the power
saving sequence. It is support 5V to LCD module power. The PANELVCC_EN signal is
generated from I306 scaler IC Gm5726H (Gm5766H).
3.2.5 R305 : ON/OFF control for LCD module back light power
ON/OFF control (BKLT_EN) is performed for black light power ON/OFF and also for the
power saving sequence.
Gm5726H (Gm5766H).
The BKLT_EN signal is generated from I306 scaler IC
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