I have encountered same problem today, twice. I was able to boot it up after few tries to start it up. It appears that power button became extremely sensitive. I tried to wiggle the power buttona little bit when it was in "pulsating vibration" cycle. No visible damage to power button, it has been in the cover for a year... Any luck with your phone?
I'm not sure what else can cause this issue, but this just happened to me yesterday.
The device forces itself off. It will vibrate after 2 seconds. If you attempt to power itself back on it may get up to the boot up screen and then force it self back off. The screen will go black but it will continue to vibrate every 2 seconds.
What I did to determine if it was the battery or power button was:
- take out battery, press the power button button for 5 seconds, re-insert the battery.
- leave battery out for 10-15 minutes and re-insert.
- Take battery out and re-insert continuously (basically just so that it touches the pins and then you remove it).
- BUT I know it's the power button because: I try to turn it on. While it's booting up i run my finger over the power button continuously. I noticed that it continued to boot up. Essentially, this forces the device to ignore any prompts that the power button may be giving it. When it was powered on the device prompted me with the quick setting menu (pop up with options to turn airplone mode on/off, vibrate on/off, and power device off).
At this point...if you're still in warranty T-Mobile should be able to replace it. If you're out of warranty then you may be able to take it to a repair center to determine if they can mess with the power button or try to do it yourself (this won't void any extended warranties you may have). Your last option would be to take advantage of the extended warranty/protection plan and exchange it.
Hi again... i'm a persistent one. I was able to fix my phone, and here's how I did it.
By fidgeting with power button while it's trying to boot up it will ignore the power down command and allow the phone to boot up. While booted I QUICKLY changed my live wallpaper...now it stays on. It was my live wallpaper but I didnt think that this was the problem because i've had it on for about 2 days now. If you can quickly change the live wallpaper that may fix it. My next guess would be to uninstall the last app you downloaded.
If that doesn't work try this while it's on: Try to rush to the settings --> Location & Security --> try a factory reset.
Recovery mode - Turn phone off, press and hold Vol Up + Home + Power. The Volume keys navigate the menus and Home actions your choice
Dialer - enter *2767*3855#
Accessing through menu - Settings - Privacy - Factory data reset.
This just happened to me a few days ago. I sat an hour on the phone with tech support and we couldn't even get it to boot up long enough to reset. I did a bunch of research after i got off the phone with them and found a feed with ppl experiencing the same problem. Apparently s2's eventually have this issue and its common. They said after awhile the power button gets stuck in the inside but u cant really tell by the feel. It said to gently rub it back n forth. I tried it then also blew into it, held it down as if I was powering on and I got it to finally stop vibrating then reboot. It literally stayed on to quickly back up before it started doing it again. If this doesn't work... Hopefully u have everything backed up because unfortunately its a wrap for that device. They will send u a replacement. They overnighted mine. I was still under warranty. Hope I helped
Once again people. This is not an OS issue. It is your power button. It will happen again. Its all over the internet. Ive swapped 2 phones because of it. Keep messing with your power button and it will turn on again sooner or later. But again, sooner or later, it will happen again.
Get an exchange and tell them it wont turn on if you have insurance
I understand that the button may cause this as well, but there could be something else that triggers this. I've personally pulled the phone apart, turned the phone on, and pushed the button out from the inside of the phone (the button was not touching). The issue still occurred...the phone forced itself off again.
After performing a factory reset the phone doesn't experience this issue nearly as much. Now it happens once a day or so, but before the problem was a lot more severe.
I had similar trouble with my Sprint GS2. It ended up being a defective power button. I bought a replacement switch, soldered it in place, and have had zero problems since.
If you don't have insurance coverage and are out of warranty, you can replace the switch yourself. Several ebay sellers offer replacement power switches for the SGH-T989 Galaxy S2. (about ten bucks)
Or, if you don't have mad soldering skills, you can ship it out to get fixed. A few sellers offer mail-in repair service:
$39 service & switch: Power Switch Repair Service T Mobile Galaxy S2 SGH T989 Samsung Fix Bad Button | eBay
$45 service & switch: Power Button Repair Samsung Galaxy s Galaxy s II Galaxy Note More | eBay