Analog Power Saving Mode. I went to reboot my husband's computer and instead just turned off the

Question

I went to reboot my husband's computer and instead just turned off the power and now he can't get it to turn back on. When he restarts it, it will run for about 2 minutes and it say's something about analog power saving mode and then goes dark. He tried switching the monitor power to "never" but now if it does go past the 2 minutes the system freezes up. He's trying to reboot into safe mode and is having trouble doing that. Could it be the graphics card and how would just turning it off mess this up?