Most older flashes that use a miniature phono plug disconnect the hot shoe center contact. Flashes that use a pc type socket, same as on the camera, or what's known as the household socket, looks just like a two blade 120 vac socket, Don't. I do have one with a permanently attached cord and a hot shoe connection, it does turn off the hot shoe connection when you remove the cord end from the flash body clip, as there is a switch hiding in the hole on the flash body for the cord end pc plug.