It looks to me like the previous owner got the input and output pins on the regulator crossed over. Your replacement might be fried now too.
The pins will be closer to one end of the regulator, see the pinout diagram below: Compare it to how yours is mounted and trace the wires to confirm.
Probably an idea to replace the diode too and orient the banded side of the diode with the violet/red wire (input of the regulator).