I thought I made a major one last night! On my amp there is a little jumper you can remove from the board to turn the amp on and off, so you can make adjustments without going up to the HU and turning it onn and off. Anyway I dropped the little jumper down on top of what I think are the mosfet transistor legs (it's really small) and it was laying on the row of little legs between the board and the big cooling fan tunnel.(you can't see the mosfets- they are covered by a heatsink attached to the cooling fan tunnel) So, because I had a dumbass attack, and it was handy, I use the small screwdriver laying there to try and knock it out (I was setting my gains again) It touched something- sparked VERY loud for a brief second and made my car power cycle (heard my radar detector do it's startup sequence again) and then here comes that lovely smoke with that great smell.....I was pretty sure I just jacked up my amp. So then I do what I should have done in the first place and get an inert zip tie to flip it out of there, and turn the amp back on. All the channels were measuring the proper voltages, so I must have inadvertantly discharged a capacitor or something in the amp. But the other scary part was I moved a jumper at some point from 4 channel input to 2 channel- and I'm listening to some music, and I'm like- where is my sub- I go back and listen to it, and it's playing midrange! So then my stomach sinks to the floor of my garage again! because I think my idiocy might have popped a $400 Sub- turned out the jumper made the amp not look at the sub input rcas, and just summed the fronts- which were crossed over at 63hz. Now everything is cool but I really felt like a dumbass- the happy ending is the gains were set and it all sounds better than it did.