If 7kVDC is present at the CRT after 30 seconds, what should be done?

When 7kVDC is present at the CRT after 30 seconds, it indicates that the CRT is operating under conditions that involve high voltage. Using caution while taking voltage or signal measurements is crucial in this situation. The presence of such a high voltage signifies the potential risk of electrical shock or damage to the electronic components if proper safety measures are not followed.

It is essential to ensure that you are using insulated tools, wearing appropriate personal protective equipment, and maintaining a safe distance from high-voltage areas while taking measurements. This careful approach helps to avoid accidents and promotes safety during the troubleshooting or measurement process.

Other options may not appropriately address the situation: disconnecting the power might not be immediately necessary and could cause interruptions or further issues; ignoring the reading is unsafe, as high voltages can lead to harmful consequences; and performing a routine check, while possibly beneficial, doesn’t inherently address the immediate concerns around high voltage present at the CRT.