I have an Axxess V10. I have some extensions (8520s) that stopped working with headsets. After determining the headset was not the issue, I swapped out the first phone. It started working. Then two more had the problem. 317 and 394 had no effect. I unplugged the endpoint, counted to ten, and plugged it back in. The headsets worked. This morning, the same thing happened to two of the same extensions. Including the one that was swapped out the day before. The same remedy fixed the issue. The three extensions are not on the same DKSC, but they are in the same cabinet. Is this a sign that the power supply for the cabinet may be going bad?