For the PSU to function correctly without damage, the technician must manually switch the PSU voltage input selector from 110-120 VAC to 220-240 VAC to match the electrical outlet specification. Power supply units with a manual voltage selector can be adjusted to suit the local power grid voltage; failure to set the correct input voltage can result in PSU damage. Configuring the workstations with an automatic voltage regulator would not alter the required PSU input settings. Checking the wattage rating is important for overall power requirements but does not relate directly to the voltage input issue described. While ensuring proper ventilation is generally good practice, it is not the root cause of the failures based on the information provided.