Sometimes you may be in the situation that a ShoreTel phone may be unresponsive or does not connect to the headquarter server. You may receive messages on phone display like No service or Cannot connect to... or the phone completely hangs (and power off/on does not solve your issue) or similar issues. This could happen because of reboot failures or firmware loading issues if you may have unplugged the phone while it have booted up and such issues or if there are firmware bugs. Often it helps to power-cycle the phone again, but if this does not help you can reset the device. We have seen this in rare situations, but here is a way how to solve this issue.
Follow this step-by-step instruction and the phone is starting from scratch: