Hi Nick,
This can be an issue with the Operating system as the hardware diagnostics passed.
Check if the issue persists in Safemode with networking.
- Follow below mentioned steps to boot into Safemode (Windows 8):
- Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
- (If you're using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, click Settings, and then click Change PC settings.)
- Under PC settings, tap or click General.
- Under Advanced startup, tap or click Restart now.
- On the Choose an option screen, tap or click Troubleshoot.
- Tap or click Startup Settings.
- Tap or click Restart.
- On the Startup Settings screen, choose the startup setting you want.
- Sign in to your PC with a user account that has administrator rights
Awaiting your response!