Heljan Class 26 O gauge diesel loco cut out problem

[paulbb]

I bought this loco some time ago and I an aware that this and other locos from Heljan in the earlier batches had component problems, particularly the gears to the wheels from the motor. Both sets of gears on this loco have been replaced (by Howes of Oxford) and are fairly new, and when it runs it is now as smooth as the other ones from this firm. However around 50% of the time this loco  seems to overload the controller and trigger the cutout on the handheld ,which is a Kent Panels Controller KFS-0, designed for O gauge. The transformer used is an old Lenz 'digital ' transformer delivering 3 amps. I have not seen this problem on my other Heljan locos -or any my Dapol locos. Just before it cuts out there is a slight noise coming form inside the loco-possbly from the pcb, and I am wondering if the pcb too needs replacing! Has anyone else had this problem, or is the solution to get a beefier controller-I believe that Helmsman ones are good, but as they now are owned by Peco they may not be available for sometime. Disconnecting the fan drive motor reduces the current draw but has not solved my problem .