The short to ground is definitely the reason you're not getting any sound. Look for any point where the signal wire, jack or plug might touch the case or even the back of one of the pots.
You can divide and conquer by retesting for continuity to ground at those same points with the effect engaged. That should let you know if the short is in your input wiring or your output wiring.
I hate to blame hardware (we've already tried it once here, and look where that got us), but if you are 100% sure that there are no shorts to ground, it could be a bad jack. Unfortunately, you'd have to unsolder them to find out.