Chosen Solution
Ipad had cracked screen and when dismantled lcd had like a liquid lines on it replaced both now no display, it makes a sound when charger is plugged in.
Did you isolate the battery before disconnecting and reconnecting the LCD, as seen on Step 35 of this guide? It’s very important to always isolate the battery before disconnecting/reconnecting the screen assembly. The issue is that the LCD connector has pins that have high voltages (i.e. the backlight is ~20V) and ground in very close proximity. When you fumble around trying to line up the connector plug to the receptacle, you can short out the voltage rail and cause damage to the components in the backlight circuit. If you’re lucky, then only a backlight filter is damaged but other times, the entire circuit could be affected. Not doing so can cause the backlight driver circuit to blow on the logic board. To test for this, plug your device into a charger or an iTunes enabled computer. Then shine a bright flashlight on the LCD. If you can see a dim image, then the backlight circuit has been damaged. If you can’t see an image at all, then it may be the LCD circuit that is damaged.
