Chosen Solution
This is the first time I’ve ever experienced this within all the phones i’ve fixed. After the screen repair for my iphone 8 plus the volume button will (from what i thought at first randomly) spam its self until volume down is pressed a couple of times. Additionally, this brings a separate issue with the power button. It will not work at times and from what I’ve concluded it works when the volume up button is pressed occasionally. One more fact to add I dropped the phone flat on its backside by accident and it made a nice clap noise and it worked normally temporarily, Before that it was rare that the power button worked. So, At first I had this suspicion that it has something to do with the back of my phone being cracked up horribly, but on my other phone that I replaced that was not an issue (i have two of the same phones got iphone 8 plus buy one get one free so i made one a work phone). My current conclusion is it might have something to do with how tight the glass back plate is inside of the phone because when dropped i realized it was more in where cracks were uneven but, now those un even cracks are pushed in and the issue happens less and is tolerable. sorry for the long post thanks for anyone who replies
It could be possible that the back glass being damaged may have damaged the volume and power flex cable assembly. What repair did you perform on the phone? I would inspect the cables and connectors for the volume and power buttons. Does the rear camera flash and/or flashlight work as well?
