Start by doing a good close up visual inspection.
A short like that is usually in the power supply section of the board and is most of the time visible. Look for a blown transistor or capacitor on the board most likely in the power section.
Here are 3 examples of what to look for. fisher-Paykel motor controller - Electronic Circuits Projects Diagrams Free
Bottom pf page on this one, right click view image to see full size. Oh no! Edo Blog, Again! - BLOG Archives: Computer and IT lx50
If you find something, pull it off, check if the short is still in the board.
Also consider how much time you are willing to invest versus the cost of replacement.
by the way, Desktop or Laptop?