This question comes up a lot, a forum search will bring up lots of threads which may save you some time in waiting for answers.
For those not blessed with thermal cameras, and in the case of a hard short, those that are, the simplest and safest way is to use a low voltage current limited power supply and DMM. Set your bench PSU to maybe 1V and set the current limit to 1A. Connect the PSU across +5V and ground (as close to the DC-DC converter as possible. Then go around the board with a DMM, set to it's most sensitive mV range, measuring the voltage across the active and passive components (start with the capacitors) that are attached to the +5V rail. The lower the reading, the closer you are to the short.
Do not share either supply lead with the meter leads, use both meter probes at each component. This will give you best location accuracy. With a 1A current limited supply, even a 3 1/2 digit 200mV range will give you 100u Ohm resolution. Turn off the PSU before clearing the fault to avoid any possibility on nasty transients.