Phone stuck on Apple logo, just vibrates when plugged in
This morning, I woke up and found my phone both unresponsive and very hot to the touch. I tried to turn it on, but was greeted with only a black screen. After waiting a little while, I took and plugged the phone into a different charger. It began to vibrate every few seconds, though the screen remained black. Oddly enough, it had not been vibrating like that when I woke up, despite being plugged in. I plugged it into a couple more chargers, including the one I'd used last night, but to no avail; it wouldn't do anything but vibrate when plugged in.
At this point, the phone had cooled down to average, or even below average, temperature. I booted up my laptop and began searching for solutions to my problem, where I saw many threads discussing this. One user suggested resetting the phone by holding the power and home buttons. I followed their advice, and saw the Apple logo appear on my screen. Of course I was elated, but then the Apple logo didn't go away. It just... stayed there. When I plugged it in, it continued to periodically vibrate, just with the Apple logo rather than a blank screen.
Others suggested plugging it in to my laptop to perform a reset. I did, but it just continued to vibrate, while iTunes told me that it had received an invalid response from my phone, My phone normally is locked, I'm not sure if that may affect it. Then I was advised to hold down the power and home buttons, resetting the phone; then let go of the home button and hold down the power and volume up buttons; then just hold the volume up button until the screen came on. Needless to say, that didn't work, either.
So, I'm at a loss. I know nothing about hardware so I haven't tried to open the phone up or anything, as I wouldn't know what to look for, anyway. At present, I'm sitting here with a cooled-down but unresponsive phone, emblazoned with the Apple logo and nothing else, which vibrates whenever I plug it in. Anyone know how to solve this problem, or if it even is solvable?