HELP!!! Finding a short to ground when nothing gets hot on the board

[supamodz]

Hey guys this is a general question about finding shorts. This problem happens to me from time to time and i have no clue on what to do.
From time to time i will get a board where i find a short to ground, so i then would inject voltage in that circuit, but when voltage is injected the voltage drops on psu but amps do not drop. When i check around board using a flir thermal camera nothing gets hot which makes the short almost impossible to find. How do you find a short when this happens? This annoys the shit out of me when i come across these types of shorts looking for suggestions.

 

[larossmann]

Are these 3115 boards with the short on the dc in?

 

[supamodz]

Are these 3115 boards with the short on the dc in?

It is a 3115 but the short is on pp1v5_s3 but i have had other boards with a untraceable shorts that always kick my ass. How do you find the untraceable shorts when they come your way?

 

[dukefawks]

"the voltage drops on psu but amps do not drop" What does that mean?
If you have a short and you inject the maximum voltage on that rail lets say 1.5V and there is no current draw then there is no real short. If you have a full hard short injecting any voltage will pull maximum current from the PSU.

 

[dukefawks]

How do you define "short"? Anything over a few dozen Ohm will not cause enough current draw to heat something up.