Mar 3, 2016
It will only go as far as the Windows loading screen, then blue and only the mouse pointer.

The power converter cord is giving the required 19 VDC.

It won't even get past this via safe mode in any configuration. I have even tried booting from a USB boot disc.

After opening it up, there were no obvious problems or loose cables. But now it won't even power on.

Please do try these troubleshooting steps that may help.
- Start with a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it up again.
- If it gets stuck on the blue screen with the mouse pointer again, press CTRL+ALT+DEL at the same time and select Task Manager.
- Once Task Manager is opened click on File on the upper left corner and select New Task then type in explorer.exe and click OK.
- If your desktop screen will come back do run System Restore and restore your laptop to an earlier date or time before the problem even happen.
- If it doesn't come back on the desktop screen your last option would be to reinstall Windows.
- Here's a guide on how to do a factory reset: https://support.toshiba.com/support/viewContentDetail?contentId=2737864