I took apart a 5200 to see what pins are in there, I've done with with a bunch of these and I'd consider myself pretty good at it. So there was three spools and two serated drivers and all five key pins were serated. I put them back together like I always did and I noticed that when I tried to pick it this time I only needed to hit one pin and it opened, thats wierd, I thought maybe I put the plug in backwards, which has never mattered before, but ya never know, so I went in and flipped it, and before re assembling the lock I checked to see if it was the same deal, now it won't lock at all, so I reversed it again, and the same thing, only the middle stack seems to be locking. I flipped it around so the bible and the lower keyway lined up and all the driver pins came up and i could push them down with normal resistance. as I looked at the bottom it did look like they slightly didn't line up so I took the plug out, cleaned it up best I could, looked for any burs or issues and put it back together with no luck. Just shy of filing the cylindar I'm wondering what could have caused this issue. The lock is fairly new I got it brand new with key and have picked it maybe 50 times, I've got others I've found in the dirt cut I've picked a lot more, 5200's hold up pretty good.
I'm just wondering has anyone else come accross this issue, oh and I did check to see that the key pins were moving like they should. Do I have a defective lock, or maybe I broke something?
The only other thing I can think is I did serated 3 spool serrated, but I don't see why that would cause this, I'll re-arrange and see if that helps.