After updating my iPad mini to software version 12.5.5 model number MF066LL/A my iPad keeps turning off from whatever I am doing

Dsnyfan0608 wrote:

How do I get it back to iOS 9.5.3?

Sorry, not possible. You cannot restore iOS9.x or any earlier version of iOS.

If your iPad is unstable, it may be necessary to restore the iPad to Factory Settings - which will reset the iPad and install a fresh copy of the most recent version of iOS supported by your iPad (iOS 12.5.5).

These support pages outline the available methods to restore an iPad - either from a backup, or to Factory Settings:

Restore your iPhone, iPad or iPod touch from a backup – Apple Support

Restore your iPhone, iPad or iPod to factory settings – Apple Support

Restore all content to iPad from a backup - Apple Support

You’ll need access to either a PC (with iTunes installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS).

Download and use iTunes for Windows – Apple Support

Update to the latest version of iTunes – Apple Support

Use of a PC or Mac computer is unavoidable. If you don’t have access to a suitable computer of your own, that of a helpful friend or family member will suffice. Alternatively, the technicians at the Genius Bar of your local Apple Store or Apple Authorised Service Provider (AASP) will be delighted to assist.

If yours is an original mini, the highest iOS it can run is 9.5.3. Perhaps that explains the malfunction.

For iPad models with a Home button, do a simple hard reset of your iPad by holding down both the Home and sleep/wake/power button simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.

How do I get it back to iOS 9.5.3?