What is a sign that indicates the customer premises may be the source of leakage?

The indication that the customer premises may be the source of leakage is most evident when leakage signs disappear upon disconnecting the ground block. This occurs because the ground block serves as a point where signals are grounded to prevent leakage into the environment. If disconnecting the ground block eliminates the leakage symptoms, it suggests that the issue originates within the customer’s premises wiring or equipment, rather than being a problem with the service provided by the external network.

In contrast, increased digital quality or no signal loss evident does not imply a leakage issue. Fluctuating readings might suggest interference or other signal issues but do not directly indicate leakage from customer premises. Therefore, noticing that leakage signs terminate with the ground block's disconnection is a clear and direct indicator of potential problems localized within the customer’s setup.