Stuck in speed repeater mode!

[hugoman]

Hi,
I have already scoured the forum for a solution to my problem. Several are here but none work. My old nav system was raymarine tridata st60 connected to raymarine autopilot st4000+ and standard horizon plotter. Everything worked well and the gps speed data was available to cal the paddle speed. I fitted a new raymarine plotter (A57) and that still output to the autopilot but the tridata went into speed repeater mode. I have removed the data cable but it will not revert back to normal. I have forced a factory reset (so lost my depth cal) but it will not budge from speed repeater mode. I have tried the three different depth-speed selected options but can't budge it. Any ideas? Is there a physical reset for example?