Are you talking about the standard wall-wart power supply or the TTPSU upgraded outboard power supply?
If it's the TTPSU - the cable on it actually has a spring clip mechanism that FIRMLY connects it to the turntable.
Always take the platter off the table before you go about moving it - once the platter is off, lock the arm in place, lift the back of the table up and carefully align the male plug with the female connector on the table. Push it FIRMLY in place being sure to keep it aligned - push it straight in - you should hear a click as it locks in place.
To remove it, hold the table firmly will pulling the spring clip mechanism back and it should pop right off.
If it's the TTPSU - the cable on it actually has a spring clip mechanism that FIRMLY connects it to the turntable.
Always take the platter off the table before you go about moving it - once the platter is off, lock the arm in place, lift the back of the table up and carefully align the male plug with the female connector on the table. Push it FIRMLY in place being sure to keep it aligned - push it straight in - you should hear a click as it locks in place.
To remove it, hold the table firmly will pulling the spring clip mechanism back and it should pop right off.