What is the first thing to check if telephones in a business have no dial tone but the embedded multimedia terminal adapter (EMTA) is powered up?

The best approach when telephones in a business have no dial tone, despite the fact that the embedded multimedia terminal adapter (EMTA) is powered up, is to check for dial tone from the EMTA using a telephone test set. This method helps confirm whether the issue lies with the EMTA itself or the internal wiring and devices connected to it. By testing directly at the EMTA, you can determine if it is functioning correctly and providing a signal to the phones. If the EMTA generates a dial tone with the test set, it suggests that the problem may be with the connections to the telephones or the telephones themselves rather than the EMTA.

In contrast, inspecting the power source is less relevant because the EMTA is powered up, indicating that power is not an issue. Replacing the EMTA should not be the first step since it may not be necessary if the device is functioning properly based on the test. Testing the connection to the network is also not the immediate step, as confirming the dial tone directly from the EMTA takes precedence in diagnosing the problem accurately.