Typically, there is only one transformer that needs to be reconfigured, as it has multi secondary taps for the drives, 24V , etc. The spindle motor needs to be be rewired for 220 but the overloads and main fuses need to be changed out as the current will now be double.
The original machines did not have a hard drive. Once a hard drive was used, it was mounted in a carrier with rubber isolators. This did not work and vibration is what made them misread. Eventually Bridgeport had the hard drives suspended on springs.
Watch the floppy as soon as you turn the machine ON. If it comes on for a few seconds, the motherboard is at least working. If not, it may be a power supply issue, or a connector issue, or a bad motherboard. If you get to video but it does not boot, it may be a CMOS issue.
The original boards were the mother board with a video board, IO board and BMDC plugged into it.