|If you have a slotted installed graphic card, remove and reseat it. It may have jostled lose a bit. Make sure that computer is off and unplugged and that you touched the power supply before touching your computer's components. Static electricity can damage components. If you have onboard graphics it probably gone south.|
Did your computer ever beep during post on start up? No all computers have a internal speaker in the case to sound audio error beep codes.
Frank Pepper: “Professionals built the Titanic, amateurs the ark”