Roman what make and model are the devices that came as donations from Italy?
Are you experienced with dental chairs? If not a few suggestions.
Most dental systems have a cut out switch under the chair to avoid crushing anyone’s foot; these often are latched (pressing the plate resets them) I've had both the switch and the operating mechanism go faulty before.
If the chair is hydraulic and the chair stuck at the top of its travel then the bleed solenoid maybe faulty or blocked.
Lee
