isn't the common approach to successively isolate sections of your layout.
but first, make sure there isn't a problem with the supply by disconnecting it and making sure there isn't a problem.
disconnect half your layout from the supply: if you still have a short, then it's in the section still connected to the supply. if you no longer have a short, it's in the section you disconnected. split the section with the short in half and identify the half with the short. Keep going until you've isolated it to a small enough section that you can isolate the short on.
good luck
greg