Does your Samsung Galaxy S5 automatically turns off when turned on and then vibrates?
Well, you're not alone. In fact, I received several emails asking me how to fix this issue. In one of the emails, the user said the problem started immediately after the phone slipped and dropped head-first to concrete floor.
There was also one owner who said the problem just started out of the blue while he was taking screenshots using the hard keys. The phone, according to him, displayed the Power off menu but continued to turn itself, then vibrated. After a few seconds it attempted to turn on, the turned off and vibrated.
Let me get straight to the point, the problem is with the Power key--it is STUCK!
To get it from being stuck, repeatedly press and release the Power key. However, to avoid data corruption due to frequent turning on and off, remove the battery first so the phone won't power on the Power button is hit.
MORE SOLUTIONS: Samsung Galaxy S5 Troubleshooting & Repair Guide
It doesn't matter how many times you press and release the button as long as you can get it out of being stuck. It is also wise to remove all cases or covers if you have one.
The normal Power key snaps when you press and release it. If it doesn't do that anymore, either the key is still stuck or totally damaged. The good thing is the Galaxy S5 uses a universal switch so you can buy the component and have a technician replace the defective one.
In case your phone is still under warranty, let your provider's technician handle all the hard work so as not to void your warranty.
In short, if you can't get the power key to work, let someone who can do it for you.