IOS – iPhone 4s stuck at apple logo in boot

Put it in recovery mode and restore from iTunes.

To put it in recovery mode, turn the phone off if possible (by holding down the power button), if not possible hold down both the power and home buttons to do a hard power off.

Finally, connect the Lightning cable while holding the home button, the phone should power up and then display the recovery mode logo; at this stage you can release the home button.

The rest of the process takes place on your computer.

The solution should be to wait until the battery is drain out and the plug it to the power source to turn it on. Everything should be back to normal.

BUT in my case, I can't wait until the battery is drain out so I open the iphone by myself then unplug the battery (~4 hours ago). Everything should be back to normal BUT in my case, it made my iphone "broken". I did a mistake (I was separating the display from the front panel!!) when I tried to "suck" the front panel. Sometimes there are some weird mark on the top of my display and touch on that area is not working :(

Though I'm not sure, is that happened because of my mistake during opening the front panel OR because I forcibly unplug the battery when the iphone is still ON.

So, it is not advisable to open the iphone by yourself. I did that because I really need it at that moment and I can't wait until the battery is drain out (even until now it still 64%).