Input constantly thinks something is plugged in

My op-1 always thinks something is plugged in. I was wondering if anybody else has had this problem? Teenage engineering told me to buy a new connector board. I did, it got here today, I installed the new one, and no luck. The op still thinks something is plugged into the input when it isn’t, and even when something is plugged into the input it just shows a silent signal. I’m at my witt’s end and just spent a good deal of money on the connector board, when I probably shouldn’t have. Any input is helpful.