I'm running CM11 with TWRP as my custom recovery.
Earlier today, I was streaming a video with flash. Then the video hanged but the kept playing. Nothing happened when I pressed the back button, menu or power. So I pressed and held the power button until the phone turned off. Then it wouldn't turn on again. I thought that the phone just locked and got stuck so I removed the battery. But it still wouldn't turn on. I can't even go to recovery or download mode. I tried plugging it in to a charger just to see if by some miraculous reason the battery completely drained, but still nothing. So that's what happened. It was working perfectly fine until it hanged.
I hope someone can tell me what happened to my phone...
update: I tried plugging my phone into a my laptop and I keep hearing the usb connect/eject sound. It seems like the phone is trying to turn on but can't. I removed it, removed/reconnected the battery, tried to go to download mode, but nothing happened, then I connected it again to my laptop but I can't hear the usb sounds anymore. So I removed/reconnected the battery again then plugged it in my laptop, and the sounds are there again.
I don't know what this means. I really hope someone can help me...