How do i reboot my phone frozen?

[Android Central Question]

I was just scrolling down the instagram when my phone ZTE BLADE A310 just stopped working. Display brightness goes down to about 50% and no button works. When i connect to PC it don't show up. I can just see driver of the device in device manager. Tried to Fast Boot, but it says "Device not found". I cant disassemble the battery on phone and don't have alternate button for shutting down. Can someone help me?

 

[B. Diddy]

Welcome to Android Central! You said the brightness dropped by 50%, but is anything still showing on the display, or is it blank?

Try forcing a shutdown by pressing and holding Power for about 20 seconds. Then wait a few seconds, and try powering back on again.