Hi Matías. The heads of conventional X-ray equipment, usually carry two cables to the head, these cables carry the supply voltage to the primary coil of the high voltage transformer which can be (220VAC, 110VAC, depending on the area ) In the cable connector that goes out to the head you can connect a lamp (filament lamp), at the time of the shot it should turn on, if it does not have a problem in the control, if the lamp is turned on you have a problem in the wiring to the head or the head itself. Discard with these tests, I hope you find them helpful. Sincerely, Carlos Torres