Check Signal Error How Then Check BIOS

Hello,

After (someone else) tried to incorrectly install a sound card, and seeing a ‘small’ spark, from then on the monitor wouln’t come up. There was a Check Signal Error. Other monitors wouldn’t work on the PC either.

I read that I should check the BIOS, but how to do this when the monitor doesn’t even come up. Any other suggestions?

Thank you in advance.