Only soldering been done on this one is at the motor end.
I have just called horizon and the speedo is now discontinued....
So no chance of repair
They did say it sounds like the sensor circuit within the speedo.
I plan to get inside the thing once I'm back at work next week and inspect just incase it's a dry joint.
I'm gonna post a new thread on fixing the sensor circuit. Hopefully someone may know. As if this has happened to me it prob gone happen to someone else too.