Question Disk read error occurred, restart the system.I can't access Bios.

Feb 16, 2019
I have an old Samsung (2008) that I opend and fixed the plug in of the power supply on the motherboard. I don't know if the notebook was working before, but when I try to initialize I got some problems. At first my keyboard was not connecting properly, and the system entered the Bios automatically and starts a continuous beep, which is normal when the keyboard is not connected. The funny thing is that I connected the keyboard multiple times and it eventually worked but when the keyboard is working I can't acess Bios nor enter the system. I received a message after the Samsung logo: Boot from ahci cd-rom; operating system not found. My HDD light was off and after I reconnected my hhd in such a particular way it came back to work. The led was now on, but I got a different message: A disk read error occurred, press ctrl+alt+del to restart the system. And I cant get through this. The hdd led was on, my keyboard is working but I can't acess the Bios or the Setup. What could be the problem ? I thought about reinstall the operational system through a USB but I dont know if this will make any difference. Should I reset Bios ?