Strange backlight issue after repair.
I'm having a strange issue with the backlight on an iPhone 6s, I replaced the display and the home button, turned it on, all worked fine, went to return it to the customer and it wouldn't turn on, I presumed it had gone flat so I advised them to charge it and get back to me. I ended up taking it back, the backlight wouldn't turn on at all, the strange part is, I have managed to get it to work partially, I messed around for a little while and found that if I plug in either the old smashed display or the new replacement without the back plate on or the sensor ribon plugged in it boots up with no backlight but works fine once booted, when it's together I'll get a flash of backlight after it has booted the first time you try to wake it with the power button, then nothing, but since it stopped working after the initial boot straight after repair there has been no backlight during boot. Worked fine after repair, now never during boot, works fine only with just the naked display panel attached, what is going on here?
Is this a good question?