RAMPing things up a notch

My RAMPS 1.3 electronic kit http://julianh72.blogspot.com/2011/08/my-parts-list-electronics.html arrived a couple of days ago.

The kit:

Close-up of the Arduino Mega:

Close-up of the main PCB board:

Close-up of the StepStick Stepper Motor Drivers:

I have spent the last couple of evenings soldering all of the components onto the main board,  following the instructions on the RepRap RAMPS 1.3 Wiki: http://reprap.org/wiki/RAMPS

First task was to solder on the resistors and other components in the middle of the man board:

Then comes various headers and jumpers, wire terminals, etc:

And finally the StepStick Stepper Drivers, and the Headers to "piggyback" it into the Arduino Mega:

I'm not exactly one of the world's greatest solderers, so I took my time, and I think everything has gone OK. I'll give it a through examination and continuity testing before connecting it up to the motors and extruder, and I'll devise some sort of commissioning / testing program (one stepper motor at a time, so that If I have shorted anything out, I will hopefully blow no more than one motor and / or one driver), so that I can confirm everything is working properly before I get into the official "start-up" testing.

EDIT 14 September 2011: I have been continuity testing my RAMPS, and it seems I have a short somewhere between my Ground and 5V lines - Bugger! Bugger! Bugger! It will probably take me a while to track down where the short is, as there are so many possible locations on the board where I may have dropped a blob of solder across the Gnd and 5V lines. (I don't suppose anyone knows any good ways to track down faults of this kind?)

EDIT 15 September 2011: Well, I can't for the life of me track down my short circuit - I am guessing it might be some excess solder that has flowed through to the top side of the board, hidden from view under a header or other component. Whatever it is, I can't get the correct voltage on the 5V line, and I can't see how the board can possibly work if it isn't giving 5V where it is required (not to mention the risk of overheating by running a dead short from 5V to ground). Looks like I may have no option but to strip the board down and start again! (Guess I had better stick to my day job - which doesn't involve any soldering!)