Looping beep/screen won't turn on after power button flex cable repair

I fixed my iPhone screen. All went well. Then I went back in to fix the power button flex cable. I replaced it. Checked to see if it worked. It didn't, so I went back in and tried readjusting the button, etc. After about 10 trials (and errors), the phone's screen didn't even turn on when I plugged it in, seems to be overheating, and the phone keeps beeping 2-6 seconds. I want to reset it, but the power button doesn't work. Thoughts on what I did to make the screen unresponsive and cause the beeps (my guess is that it is in a restore loop).

Thanks in advance for any help.