Chosen Solution
I have an iPad Air Wifi 1st gen for screen repair. According to customer, the power/lock button worked fine before. I smoothly removed the old screen, put on a new screen. Everything works perfectly. However, I notice the power/lock button doesn’t work properly. The symptom is very strange, never seen something like this before: When I pressed power button, the iPad turned on perfectly fine. When I pressed power button again, it won’t go to sleep mode. It doesn’t matter how long I keep it pressed, nothing happened. The “slide to power off” won’t come up. After 2 minutes, the iPad went to sleep mode automatically (because the auto-lock was set to 2 minutes). If I press the power button again, the iPad will wake up. But it won’t go to sleep again until 2 minutes passed. If I press and hold the power button and home button at the same time for a few seconds, the iPad will soft reset and restart as normal. I thought the power flex might have problem, then replaced it with a known working power flex. But it made no difference! The power button can only wake up the iPad, but it can’t put it to sleep or turn it off. I reset the iPad (haven’t restored it yet, just reset) to original factory setting, again made no difference! Any help will be highly appreciated. It almost drives me mad!
Have you ruled out it being a bad - new screen/digitizer assembly? I have had power button/sleep issues caused by bad holofect communications. The problem that are normal, is that the device boots up but then power button wont do anything but turn it off (you said you couldn’t get it to turn off either though only soft boot) Can you still try with the old screen on it and see if it still works? If it does, it points to a bad replacement screen. Check this out for some other things you can check on the digitizer it self to see if it is missing component that cause issues like this https://youtu.be/fdzn3ZZsPyc?t=14m39s Good luck!
If you haven’t already try another home button as a faulty home button assembly can cause interference / issues with the power button.
I had the exact same issues you described, also with an ipad air 1st gen. I tried home button flex among other things that you were suggested here but what did it in the end was just to update from iOS 11. I’m aware this was a year ago for you and maybe there were no update available but if other people come across this they might want to try to update. Have a nice evening
