I won a Bernina 230, too. It's my main machine. Sometimes the feed dogs get knocked so they won't come up high enough. Sometimes the feed dog stepping motor has issues. Or the connection from the circuit board to the stepping motor may be loose. When you say, "you've cleaned," does that include removing the needle plate, and cleaning under the feed dogs? I've seen some very packed feed dogs, and the owners didn't know they were suppose to clean under the needle plate. I hope you're able to get it going.