My iPhone 6S was stuck on Apple logo for 30 minutes when I am trying to update and restore it with iTunes. How it is going?
Sounds like the software crashed. You may want to try hard reseting your iPhone 6, then starting the restore over again. To hard reset your iPhone, press and hold the power button and Home button at the same time until the Apple logo appears on the screen. If that doesn't work, a 3rd party security software installed on your computer may have prevented the update and restore. Apple has a really good guide to address this problem— Google "resolve issues between iTunes and third party security software" (can't post the link on this forum for some reason). It could be a Lightning cable issue, or you may need to DFU restore your iPhone.
This doesn't work. After doing this, the iphone was stuck on connecting to iTunes screen forever. The only way is to restore it. but when it did this, iTunes says, The iPhone could not be restored. An unknown error occurred (4013).
You can try to go to DFU mode by the following process to fix iPhone stuck on Apple logo 1. Connect to the computer 2. Turn off your phone 3. Hold the power button for 3 seconds 4. Hold both the power and home button for 10 seconds 5. Release the power button but keep holding the home button for 15 seconds 6. Itunes will then alert you that your phone is in recovery mode
It's a good idea to restart the iPhone in the right way, please refer to the Apple website. Press and hold the top (or side) button until the slider appears. Drag the slider to completely turn off the device. Once the device is turned off, press and hold the top (or side) button again until you see the Apple logo. In addition, recovery mode is also helpful in fix iPhone stuck on Apple logo.