LiftMaster has no power
I recently replaced the drive gear. I put everything back together except the back "door" to the cover. I plugged it back in to test it before I closed everything up. It worked. I forgot to unplug it before I attempted to put the back cover on (the one with the logic board and wires). I heard a noise (kind of like a tsst) and all of the power to the unit was gone, even the doorbell opener on the wall. What have I done? Can I fix this myself or do I need to call an electrician, handyman, or both. Help!!