P500D Units that will not shut down properly due to failure of the UPS.

P500D Units that will not shut down properly due to failure of the UPS. See long description: When a SHUT DOWN is attempted, the IUI Console starts to close all programs, goes to a Text screen with the last line displaying POWER DOWN. The lights may go off on the UPS but 120 VAC power is not removed from the IUI Console, Saturn Digital or System Controller to complete the SHUT DOWN. The computers continue to receive 120 VAC power from the hospital power, via the PDU CB5 which feeds the UPS. The only way to complete the Shut Down is to turn off CB5 on the PDU or turn off the Main Wall Breaker. Once PDU CB5 or the Main Wall Breaker are turned back on, the IUI will turn on and start to boot. If the operator does not press also the ON BUTTON on the console, parts of the system do not power up and error "3601244 Tube Cooling supply error" is reported. (PDU provides 120 VAC for the tube fans).