how to fix error 40 in iPhone

Hi anaworried!

Error 40 is a hardware problem. I put a link to solve this problem: Get help with iOS update and restore errors - Apple Support

This is what it says about your error:

Check your hardware

If you see error 53, use these steps.

If you see one of the errors below, you might have a hardware issue:

• 1, 3, 10, 11, 12, 13, 14, 16
• 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 56
• 1002, 1004, 1011, 1012, 1014, 1667 1669

Here's what to check. Try again after each step:

1. If iTunes is already open, quit and reopen it.
2. Check your third-party security software.
3. Make sure that your USB cable, computer, and network are reliable. Then try twice more to restore your iOS device.
4. Check for outdated or modified software.

If you still see the error, contact Apple Support.

I hope I have been helpful.

A greeting!