A torsion spring under tension can take a finger or worse, and on a door from the late 1980s the spring has had three decades to corrode a little where the winding cone grips it - that's exactly the kind of spring that doesn't behave the way the internet tutorial expects. Cable fraying, loose track bolts, and worn weatherstripping are fair DIY territory on any door. Spring replacement, drum work, and anything involving the winding bars is not something we'll walk you through over the phone, and we won't sell you the parts to try it solo. If your opener is just not responding, check the wall switch and the breaker before you call - that's a five-minute check that saves you a visit fee more often than you'd think.