Massey 5445 Powershuttle problem

I'm wondering if anyone else has come across this issue. Its a 2004 MF 5445 Hi Vis Speedshift with Powershuttle.The tractor was working fine with no issues when turned off, after an hour when it was restarted the poweshuttle would not work in either direction, none of the forward or reverse powershuttle dashlights would illuminate. The powershuttle will only engage and operate when the differential button is switched on.

I replaced the BOC (bottom of clutch) switch in the hope that it would fix the problem but it hasn't. I've tried disconnecting the battery and leaving it over night in the hope that it would reset itself, but to no avail.

I'm checking the electrical connections to the Autotronic 5 controller with the help of the workshop service manual but cannot find any electrical problem so far. I'd be very interested in any suggestions you have as to what the cause of the problem might be. Thanks.