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Phone constantly vibrates even when off after a drop from the top of the stairs to a slate floor (surprisingly everything including the case is fine. I assume this is a hardware fix. Any ideas where to start?
Hopefully just a bad vibrator. If you are planning to open the device, buy a replacement vibrator just in case because opening the device and putting the device back together is fairly complicated due to the plethora of ribbon cables it has. A replacement vibrator can be bought online on sites such as eBay: https://www.ebay.com.au/itm/Vibrator-Vib… Here is a guide, the main board may need to be removed to unplug that vibrator: HTC One M8 Motherboard Replacement
