Thr RTC battery in the laptop needs to be replaced.
This battery maintains the BIOS settings when the laptop is switched off.
When it has failed the BIOS can become corrupted which prevents the laptop from starting properly.
Here’s the service manual for the laptop. Click on Coin-Cell battery in the Contents section to view the necessary pre-requisite steps and then the procedure to remove/replace the battery.
The battery is a non rechargeable Lithium battery, usually a CR2032 (battery type is printed on the battery)and lasts ~5 years. It is commonly available, even supermarkets sell them.
When removing the battery remember which way it was installed (usually +ve on top) so that the replacement is installed the same way.
When the new battery has been installed, when starting the laptop, press F2 to get into BIOS and correct the date and time. Also see the instructions in BIOS how to set the BIOS to the default settings (usually it is F9 but may be different) Whatever it shows, reset the BIOS to default and then save the changes, and restart the laptop.
Hopefully it should be good to go.