Q: i phone 4 no screen

Hello Dave,

Thanks for using Apple Support Communities.

If your iPhone's screen is just black, then I'd like you to please follow the directions below to troubleshoot the issue.

If you see a solid color screen (black, white or blue)

1. Plug in your device to a power source. If you see the low-battery screen when you plug in, let your device charge for at least 10 minutes (20 minutes for iPad) before using it.
2. Reset your device while it's plugged in.
3. If resetting doesn’t fix the issue, restore your device.
4. If you still see the issue after you restore, contact Apple Support.

Get help with the screen on your iPhone, iPad, or iPod touch - Apple Support

Have a good one,

Alex H.