Boss DD-3b wiring

[monprintemps]

My Boss DD-3 stopped working (won't power on/light doesnt come up) the other day and when I had opened it, a black wire coming off of #24 off of the circuit board was disconnected. Not sure if this is the source of the problem, but does anyone know where this wire goes? I think that my DD-3 is an older DD-3b. I have the schematics for both the DD-3t and the DD-3a, but I can't find one for the DD-3b. Also, I'm not too familiar with electronics, so any help will be much appreciated. Thanks

[doctor]

This is the reason. Connect this wire to the ground pin of the connector "input".