Mountfield M725 stalls when cutter engaged

[lurcher]

Hi, I have a nearly new Mountfield M725 that stalls when the cutters are engaged. It's as if there is a safety switch that I don't know about.
Any ideas would be very much appreciated.

 

[pugaltitude]

There should be safety switch on seat area, cutter, grassbag switch and possibly a neutral switch
Usually its the grassbag switch at rear that gives problems.
There is a little electric circuit in a grey box that has fuses that causes problems too.