Those digits are fairly important to EEs. Common switch mode power supplies are not picky about input voltages and generally have a wide range of operating vol

Those digits are fairly important to EEs. Common switch mode power supplies are not picky about input voltages and generally have a wide range of operating voltages, having the switch on 230 likely just knocked 20 volts or so off the input voltage to keep the 230 below the max voltage, not half it. The reason this eventually started causing problems is probably because your wall voltage has dropped and/or components in the supply aging and drifting from spec meant it could no longer maintain good clean output which triggered a safe guard in the computer.