Probably damaged the u10 ic chip in the middle of the HB. These suckers are fragile! https://www.youtube.com/watch?v=lJgv6SdN... Ive tried a few as a test, first batch failed but got better with practise and now successfully been replacing the chips. This is only for the feedback touch element, not the touch id!
My experience on this is two fold... you either break the HB or the screen flex is faulty. Of hundreds ive done this is the only two issues ive seen. I thought i had a broken HB on one of the latest repairs, tried 5 different screens and gave up. Turns out i had a bad batch of non oem screens that had faulty flex (serious bad luck there!). Just be careful with the HB removal (gently pry up a little to the right, a but of iso spray and a playing card and comes out nice, be gentle around the u10 ic chip (the large ic in the middle of the HB), it can be replaced but you need skillz! Get quality screens, i know people like to maximise profits by cheaping out on screens but its not worth it for the ip7 as it stands, you only end up moving the HB more and that causes extra stress on a already weak cable. We go refurbished original LCDs from now on and have great results, around 95% of all screens work perfectly. Ive not seen any issues or with SW or just by opening them up, IMO they are just myths for bad repairs.
This happens when you don't use a genuine home button, it locks when the smart case is on back or front. Add the original or genuine home button (the ones that come with replacement air screens tend to be copies) and the problem will go away
I actually fixed a customers error 53 today... was kinda shocked! We did a screen swap a few weeks ago and customer got in touch to say he had error 53. There was no evidence of any damage to the home flex or long flex, both were properly seated. As a last resort we tried replacing the long home flex and woolah no more error 53! I dont know if it was shorted (certainly looked fine) but very relieved it worked!
also make sure your wearing esd gloves or wrist strap, ive killed a couple of display assemblies from shocking them but none since ive gone the glove method :)