Oh shit!

Uuh, where is my multimeter? From the Technics SL-1210 MKII FAQ:

Contrary to (popular?) belief there is no way to lose true 0% pitch when the slider is in the middle - no matter how you hack it. When in the middle there is a switch which is thrown which bypasses the pitch slider and the motor is now crystal locked at the exact speed. But, if your deck is messed up in this area when you move the slider in the + direction, for example, it will slow down at first and will then move to 0 and then will speed up as you move it more in the + direction! In other words you now have 0 at two places. So this is for reference if you need to get your pitch slider so that 0 is really in the center. Open up the base, look where the pitch pot is. There will be a hole about 3-5mm in diameter where you can see a small pot on the other side. Hook up a multimeter to that pot (again, connect to the center lead and the one nearest the edge of the board I think) and use a small adjustment screwdriver to adjust it to 2.7kOhm.

Ok…