The answer depends on condition and whether or not most parts are present. Others likely have much more experience than I do, but so far I have turned down several that appear to be missing too much, have been seriously hacked, and/or are in too rough shape and have been successful getting all others running as they should. I have only bought one EM that the owner said was working well (it wasn’t and even had a bypassed fuse that could have been dangerous).

If an EM has been sitting, it’ll likely have dirty contacts and gummed up steppers. Machines that have been sitting in a basement or in storage will usually not work immediately when first plugged in. They may have also been put in storage or haven’t been played because something went wrong with them and the owner didn’t have the know how to repair them. And then even if the machine is “working”, there’s no guarantee it’s working as it should or doesn’t have potentially dangerous hacks in it unless it has been gone through by someone with some expertise.

Before I go check out a machine in person, I always ask the owner whether or not they think anything is missing and don’t bother to ask if it’s working as I expect it isn’t and actually hope this is the case as I look forward to doing what it takes to make it so. If you go this route, learn to read schematics and get good at diagnosing problems. Older machines usually just need a new cord and new rubber ring kit and a good going through. If you’re willing to tinker and learn, getting an EM in your lineup should be worthwhile.