@jikkejikke black screen with a blinking cursor is commonly caused by a failed HDD. Your computer can't access the OS.
Try to enter the BIOS by restarting your computer and keep pressing F2 key when the Samsung logo appears. Once in the BIOS see if your HDD is found . If not, you will need to replace the HDD.
You could also try and set the boot order to USB and get a bootable USB drive. Boot from that and try to access your HDD.
You can download the service manual for your computer [https://www.nodevice.com/service-manuals/pc/samsung/np-r440-ja04in/424557|from here]