What is the first action to take if coffee spills on the RTU and it goes blank?

In the event of a coffee spill on the RTU (Remote Terminal Unit) that causes it to go blank, the priority should focus on ensuring safety and preventing further damage. The most appropriate first action is to inhibit the RTU on the non-working side. This action helps to isolate the affected system before taking any additional steps, such as cleaning or repairs. By inhibiting the RTU, you are effectively preventing the system from attempting to operate in a compromised state, which could lead to further issues or potential safety hazards.

Choosing to inhibit the RTU allows for a precautionary measure to control any unintended operations while preparing to assess the damage and seek maintenance assistance if necessary. It creates a safer working environment and allows for a more systematic approach to troubleshoot the situation without escalation.