Device boots (or partially boots), displays HP logo briefly then black screen with slight backlight. Cap lock light working when pressed.
If the device is put into sleep mode by pressing the power button after the above, when pressing power again to awaken, normal windows is available via an external monitor. Have tried resetting, hard shutdowns, diagnostics, tests etc. Will boot in safe mode ok. Possibly a display/graphics issue? But the screen is working in diagnostics and safe mode so not sure why it won't work in normal windows.