I think my 727 is fried. Now I'm at a crossroads...

Oh believe me, PLENTY of swear words/wrenches/empty beer cans have been thrown around. But I only have myself to blame...after all, I could've just taken it to a shop this whole time, but nooooooo...I'm stubborn and want to learn how to do this.
That's why I have a sigh on the front door stating, "ENTER AT YOUR OWN RISK".