Answer: please see followings:

[Procedure]

1. Reboot the machine

　 Make sure if you can reboot machine with the green power switch which is on the front panel of machine. If the front panel green power switch did not work, use the other power switch where is on back side.

2. Please note that below things if your machine got frozen one more time.
　(Please tell us when you contact us)

　It should include the following items:
　 ・The timing of your machine got be frozen.
　 ・What is on the display when it got be frozen?
　 ・Does the reset switch activate?
　 ・Does the power button on the front panel activate?

3. Check the Firmware version (Please tell us when you contact us)
　 It will be appeared on the display right after you powered on.

Or you can see the below display after you hit key 2 times with [Local] display.

4. Please contact us if you still keep having this issue.