Before plugging the thing into the wall again, perform a few simple checks with an ohmmeter first. It sounds as if you have a short circuit somewhere. Those are usually very easy to find (unless they're intermittent).

If you do find that a short exists, you can narrow down the possibilities by selectively disconnecting parts of the circuit. For example, if a resistance measurement shows, say 10 ohms of resistance between the power leads, try pulling out the common-mode choke near the power input. If the resistance goes way up, then the problem lies with the choke or points downstream of it.

Since you have a schematic of the power supply, it shouldn't be too hard or time-consuming to devise and execute your own troubleshooting strategy.

And, once again, it's impossible to overestimate the value of a thorough, careful visual inspection. Use a magnifying lens and a bright light and look at both sides of the circuit board. Especially in cases like this where tapping affects things, a visual inspection will frequently reveal your problem.

Don't power up your Mac again until it passes the ohmmeter test, unless you like buying fuses.