Q: iPhone 6s passcode stopped working

Thanks for joining Apple Support Communities, harpeagle50.

From your post, it appears you're having two issues with your iPhone 6s on iOS 9.3 with your display and your passcode. Since your screen is blank, helping you sort out your passcode would be futile, so I'll focus on that one first.

Get help with the screen on your iPhone, iPad, or iPod touch -- Use this article to troubleshoot your iPhone's display.

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled -- Use this article to regain access to your iPhone.

Hope this helps!