Please do try these troubleshooting steps that may help.
- First is to do 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.
- Next to try is to remove the HDD off the laptop then power it and see if the laptop will get pass the Sony screen.
- If the laptop will get pass the Sony screen without the HDD that means the problem is your HDD.
- But if the laptop will still stay on the Sony screen without the HDD that means the problem lies in the motherboard.
- Do try to open the laptop and remove the CMOS battery for a second then test it again.
- If all these will not work and if the laptop is still under the factory warranty, do contact Sony for a repair.