Mac mini will not prompt a screen after powering on

I have a work college that has a mac mini, it was working fine last night and when she woke up this morning, their was an error on her screen. So she brought it to work for me to take a look at and nothing is prompting on the monitor for me to see while its powering on. There's nothing from with the hdmi chord i'm using. She believes its a virus, was just wondering if their is anything i can try to help the situation, Thanks