iphone 6 plus screen on/off switch not working at all

Howdy there bobbyfin3,

It sounds like your Sleep/Wake button doesn't seem to be working at all. I would use the troubleshooting in the following article to either resolve the issue or reach out to Apple if needed:

Get help with buttons and switches on your iPhone, iPad, or iPod touch

If the Sleep/Wake button doesn't work

On iPhone 6 and iPhone 6 Plus, the Sleep/Wake button is on the right side of the device, near the top. On earlier models, the Sleep/Wake button is on the top of the device, toward the right side.

If the Sleep/Wake button isn't working and your iOS device is on, follow these steps:

1. Press and hold the Sleep/Wake button.
2. If you see "slide to power off," turn off your device and then turn it on again.
3. If you can't turn off your device, try to reset it.
4. If the Sleep/Wake button still doesn't respond, follow these steps and test again:
   • Check for debris or dirt around the Sleep/Wake button and clean it with a soft cloth.
   • Remove any case or film.

If you can't turn on your iOS device, connect it to an A/C adapter. When your device is charged, try the steps above again. If the battery is extremely low on power, your device might display a black screen for up to 10 minutes (up to 20 minutes for iPad) before you see a charging indicator on the screen.

If you have an iPhone 5 and the Sleep/Wake button still isn't working, or works intermittently, you might be eligible for this replacement program.

If you've followed the steps above and the Sleep/Wake button still doesn't respond, if it works intermittently, or if it's damaged, contact Apple Support to set up service.

Thank you for using Apple Support Communities.