There aren't any filter capacitors between the AC mains and the ground as these are Y2 EMI/RFI filter capacitors while the Mac Plus only has 3x X2 filter caps who sit between the mains near the power switch. However since these are behind a fast 1.5A blowfuse, it's unlikely they trip a standard RCB.
There are different types of circuit brakers in houses: the standard one's, RCB, only switch out on overload or short circuit, however others watch for loss between the fase and the ground,RCBO's,: I think it will be this one's that trip in your house.
Can you confirm this ? Otherwise post brand and model/type number of the circuit braker.
I also think there's a fault somewhere on the Analog boards where there's a loss between the mains and the ground, the AC circuit before the transformer is most obvious, however a loss on the DC side to the ground can also trip these RCBO circuit brakers.