If your PC does not boot and stays with the splash screen:
That probably means your SATA connector is not properly connected.
You can follow the steps:
1 Put off the SSD and the Black plate for SSD of the PC
2 Open the back of the PC (4 black screws in the corners)
2 You will see the SATA connector as the photo below:
4 Take it off and put it back, be careful, this is really sensible.
5 Screw back the 4 screws and the plate.
6 Try the PC.