Audio but no Visual after thunder storm.

Our Mac Mini is hooked up to a Tv/Computer screen via the DVI cable. Following a recent thunder storm, we have no visual on the screen. The Mac Mini boots up and we can hear the start up sounds, mouse clicking and keyboard noises but the screen stays black. The screen itself works as we can still watch Tv fine. We purchased a HDMI cord incase the DVI cable itself was ruined, but that didnt work either. The screen just shows 'Check Signal Cable'.

Any sug