Chosen Solution

Hi i have an iPad mini and i was trying to fix the backlight issue . (I open the screen and i send light to it to see whats going on) . Firstly without make anything the only problem was the blacklight i mean that if you send light to screen with a flashlight you could make anything you want in your device .But now when the apple logo appear make something like flickering (it appear-disappear).and the problem with the blacklight is the same Update (10/30/2017)

the “flickering"problem appear when i change this component

Is this a picture of your device or just a picture you found on the web? Have you tested the individual components in the backlight circuit? I would start by validating that L2200 is in good condition. Then check the diode to insure it is working properly, even if you replaced it. You may have damaged it with too much heat while soldering it. I wold also check the coil. If needed, you may need to replace all of those components plus the driver IC.