Hi Dave ,
add a lable/ marker to one of the red wires that connect to the control pcb
then take a photo or make a note
changing the wires over one by one is a very good idea
but you need to have a plan B if some wires come off by accident ( been their

)
PS just spotted the cable ties your photo on page 3 gives all the detail you need
PPS using your photo just added your wire colours to a diagram of the control
not sure of order of mains wires but ties help to get them right
Hi Stuart ,
the relay board is in the control box with the speed control PCB
the relay circuit could be use full while fault finding
since it is an interlock for the power and switches the 27 ohm braking resistor
the damaged filter PCB is in a plastic box hidden by the motor cover at the rear of the machine
John