Ok, the snap you're hearing is a relay clicking. That's a good sign.
Does the standby light flash? If so, how many flashes in between the pauses?
If you're getting a LED on the front panel, the power board fuse is good. Don't be intimidated... the test points will be labeled. Just be sure to unplug all other boards from the power board first. Then put your red lead on the test point, and the black lead on the chassis or back of the plasma panel. The test points will be something like "Vsus" or "Va" or "Vscn." The nominal values and tolerances will be on a sticker near the power board.
Let me know if any are abnormal.