well, I must have done something correctly because, when I reinstalled the BIOS jumper in the regular 1-2 position, everything started correctly.
I just don't know which proceedure actually worked. can anyone help me to understand this?
When you put the jumper back in the normal position it just put the BIOS back to the default setting. Many times when we are having problems with a board the 1st thing we do is clear the BIOS. You can clear the BIOS with the jumper or by just removing the battery for a couple of minutes. After BIOS is cleared you would not need to reload a BIOS you just need to access BIOS and replace any changes you had previously made from the default settings.
Thank you so much for your excellent explanation. I thought the BIOS had been completely wiped out; my mistake.