Acer AL1702 Service Manual - Page 7
Browse online or download pdf Service Manual for Monitor Acer AL1702. Acer AL1702 38 pages. 17-inch lcd monitor
Also for Acer AL1702: User Manual (17 pages), User Manual (20 pages), Service Manual (49 pages)
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3.
Interface Operation
3.1
Top (Circuit diagrams MAIN PWB 2 of 8)
This page is function block. (1) power. (2) VGA & DDC interface. (3) scaler MST8111B. (4) panel interface. (5)
audio (option).
3.2
Power (Circuit diagrams MAIN PWB 3 of 8)
3.2.1 P301 connector
A 5V power supply for LCD module, MCU, logic. And a 12V power supply for audio function. It is
generated from the P301 connector.
3.2.2 I301 : 3-terminal regulator
A 2.5V power supply for scaler IC I305, it is generated from the 5V source.
3.2.3 I302 : 3-terminal regulator
A 3.3V power supply for scaler I305, it is generated from the 5V source.
3.2.4 Q303, I312 : 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.
3.2.5 R306 : 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.
3.2.6 Q301,Q302 : Adjust back light luminance for LCD module
It is adjusted back light luminance control (BKLT_ADJ) is performed for the back light luminance.
3.3
VGA & DDC interface (Circuit diagrams MAIN PWB 4 of 8)
The analog video signals input, the AC-coupled video signal video signal is used to clamp the black level at
0V. and H/V sync to sclaer, and DDC plug & play function.
3.3.1 P302 connector
The video input signals from the P302 connector.
3.3.2 I304 DDC EEPROM
This IC is support DDC2B of the VESA standard, also plug and play for the PC host.
3.4
Scaler MST8111B (Circuit diagrams MAIN PWB 5 of 8)
The I305 is scaled converter LSI for the LCD monitor.
The analog R, G, B signal input entered from the video input circuit is converted into the digital data of video
signal through the incorporated A/D converter. Based on this conversion, this device performs interpolation
during pixel extension. These interpolation digital data are transformed to LVDS signal. The I305 source
voltage is 3.3V and 2.5V, the device clock frequency is 14.318 MHz. The device control signal is from MCU
through the 3-wire bus.
The I305 scaler has support OSD function.
3.5
Panel interface (Circuit diagrams MAIN PWB 6 of 8)
3.5.1 P305 connector
The P305 is LVDS bus, output to LCD module. The output voltage is 5 voltage.
3.5.2 MCU (Circuit diagrams MAIN PWB 7 of 8)
The I307 MCU is system processor. It can programmed scaler, control power save sequence for the
system, input keypad function, output LED, control audio function, and ISP / DDC2Bi function.
AL1702
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