Last week we received an iPad Air 1 in the post from a regular repair shop. This iPad air was showing nothing on the screen, no image or backlight.
At first we saw damage to the LCD so checked that this was not the only fault, which it wasn’t. After testing a new LCD the problem still persisted. We removed the screen and board covers to check the components and saw that L7001 was burnt. We checked this and it was on the PPVCC_MAIN_LCD_SW_CONN line. This is the main power line for the LCD so this is the most likely filter to blow when the screen is disconnected whilst the iPad is turned on as this line will be out putting 4.7 volts which is easily enough to blow a filter.
After checking that this power line was not also short to ground we removed L7001 and replaced with another 120Ohm 1.5A filter (The same as used in the iPhone 6s).
After replacing this filter the image and backlight both returned back to normal and we had a fully working iPad again. This was returned and we had another happy customer at the end of it.