One of the most popular questions is where to look and what to check on the decks to see if they're in good shape. Unfortunately there is no real straight answer to this question. A lot of times people sell their used SL through the classifieds, others relay their intention to sell just by telling a lot of people, because they know the SL is incredibly popular. You should also make sure to call any store or other company that might have anything to do with turntables to see if they have them for sale. What probably works best is to tell a lot of people you're looking for them and have them contact you if they find anything.
Once you found one or more used turntables there are a few things to look for as to make sure they are in good condition:
The turntable as a whole should look in good shape. Look for any signs that might hint to abuse like heavy scratches, dents, melted plastic/rubber etc. In general it should look like nobody dropped it on the floor or something.
Have the owner install the turntable on a soundsystem to see if any sound comes out and to ensure the thing actually turns. While the platter turns check to see if the spindle is straight, a crooked spindle will make an abnormal wavy motion and if this is the case the turntable is useless!
The most important feature of the SL is the pitch control. Once the deck is turning you should put the pitch in the zero-position and then move the slider up and down slowly while looking at the pitch-dots on the turntable. Check that the dots speed up or slow down in a gradual, non-interrupted manner depending on which way you're going. Make sure they don't "schock" heavily as this is a sign of the pitch regulator being screwed up.
The second most important feature on the SL is the tonearm. It should feel solid and the screws on it should all be in place. Check that the arm-height adjustment ring, the anti-skating control knob, and the cueing lever function (The anti-skating control knob doesn't immediately do anything visible so just make sure you can turn it). Don't forget to see if the balance weight isn't missing!
Take off the platter as explained in "Opening the top" and see if the inside doesn't look like the inside of a dumpster. Excessive amounts of cigarette ashes point to heavy smoking by the owner while being used. This sometimes also shows in the grey cover of the SL1200 turning slightly yellow from the smoke.
If none of the above problems show up in the SL it can be deemed save to buy. Don't forget to ask for the cover, the 45-rpm adaptor and maybe the proof of purchase as this will ensure that the turntable is complete and comes from a reliable person.
