A few months ago I performed a DIY screen replacement on my 5a after a drop. Everything was working well until last week. While watching a video on Vanadium, the screen went black. A restart did not resolve the issue. Apart from the screen, the phone seems to be working (haptic feedback on power button, phone calls can be made over bluetooth, etc). I decided to try another screen replacement. Unfortunately this new screen is also always black. While it is possible IFIXIT sent me a faulty screen, this option does not seem likely.
Any advice as to how I might troubleshoot this?
Would trying to get in to safe boot or recovery mode potentially be useful? Since the screen never displays anything, even on boot, I am dubious of this approach.
I should add that at least once before, watching videos in Vanadium also resulted in a black screen. However, I was able to recover use of the screen with a restart.