My phone is on diagnostics and won't restart

See this Apple support article—>If your iPhone, iPad or iPod touch won't turn on or is frozen – Apple Support

If this doesn’t work your phone most likely has a hardware problem. Use the Contact Support link at the top of this page to discuss repair options.

My iPad is on diagnostics Wht to do

Follow the instructions by clicking the link in the Apple Recommended post at the top of this page.

How can we make the phone turn on again