RL02 weirdness

Now that I have my RX02 drive working I have started to take a look at the RL02 drives again. I hooked a scope up to the sector transducer and sector timing test points, and they look nicely aligned. So I moved on. Then I hooked up the scope to the TP1, TP2 and the sector timing TP and compared it to the output in the RL02 tech manual. S1 was fine but S2 was offset in the wrong direction (probably need to see page 3-8 in the manual to understand). I had a look at where the heads are connected to at up was connected to down and down was connected to up. Without understanding the consequences I switched these and loaded a pack. Unfortunately I heard a horrible sound and I now have a thin black ring on the bottom side of my platter, which I am very upset about. :( I unloaded very quickly but I think the damage is done. Why would the heads be installed this way? and why did it destroy my platter when they are connected "correctly"? Does anyone understand what might have happened? Thanks, and sorry for destroying a pack :( Aaron.