Set all MSEL switches to "1" by mistake
From Terasic Wiki
Q:If you set all the MSEL switches (SW10) to "1" by mistake, you may see the SoC is incredibly hot after powering on the board. Why this issue happens?
A:This is because the device would be a invalid state when all switches to "1", this would cause device high power and lead to incredibly hot.
So, customers need follow our user manual to use the DE10-Nano board, take care of the MSEL settings and do not set all the MSEL switches (sw10) to "1" .