When a machine 'sticks' on splash screen' it is usually a sing the hard/drive has not booted( failed)
If it was running on battery only' then retry withe mains unit in.
With thebpower unit in
If still no joy, repeat holding power button down until it shuts down, wait a moment then try again.
Othervwinsevto the supplier it goes.
Hopefully all your stuff is backed up onto a DVD/CD or other device.