Connecting the LCD panel from iPad to personal computer

A broken laptop or tablet can be miserable to throw out, especially if his motherboard / video card / processor has burned, and the display is in perfect order. In this case there is an exit: you can connect the LCD from a mobile device as a second / third screen to a personal computer. Best of all, the LCD display from the latest iPad models with a size of 9.7 "and a side resolution of 2048x1536. The Warsaw University student Andrzej Surowiec managed to connect the iPad to a PC via DisplayPort at maximum resolution.

A broken iPad with a working display can be bought for ridiculous money. Moreover, you can directly order this item from China, it will cost about $ 55. So this trick is even cost effective: you cannot buy a display for a PC with this resolution even cheaper.

Polish student for his conceptual project bought a panel LP097QX1-SPA1 manufactured by LG. This is not an exclusive part for Apple. In addition to the iPad tablet, it is placed in some other Chinese-made tablets.
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The LCD panel is equipped with the eDisplayPort interface, which replaced the LVDS, and the essence of this hack is to connect the eDisplayPort to the standard DisplayPort on the video card of the personal computer.

The author could not find evidence on the Internet that eDisplayPort is compatible with DisplayPort, so I decided to check it out by connecting the wires from the cables through a homemade interface board.



The cheapest adapter for the iPad LCD panel is the Molex 502250-5191, which costs about $ 7. Then the wires on each side are simply soldered to the corresponding contacts on the homemade board. The scheme can be taken on github .

The electronics of the LCD panel itself can be powered directly through the interface board, it only needs 3.3 V to 500 mA. But the screen backlight requires some kind of external power source, because the backlight consumes up to 4.4 watts. Rummaging through the schemes of the iPad 3, the author managed to find information that the screen backlight consists of 12 rows of white LEDs of 6 pieces each, and all together they need a power supply of 20 V. In the experimental model the author did not bother with a beautiful scheme across the 68R resistor to each cathode, so each row of LEDs pulled 17 mA. A voltage of 20 V can be obtained from a five-voltage source through a step-up converter TPS61175.

Oddly enough, the whole structure worked without glitches like a regular computer display.