Unresponsive dvr following firmware upgrade

Over Christmas I selected to install a new firmware. After an extended period (more than a day) my Tablo was still not responsive and was quite hot to the touch.

Holding the reset button does not visibly alter the state of the device as indicated by the LED never blinking, never showing an IP address assigned by the router not having a WiFi broadcast from the tuner.

Are there any steps that can be performed to (attempt to) restore the device to operation?

Hold the reset button (tiny blue button on the back of the unit) on the back for 30 seconds. While still holding the button down, unplug the power cable from the Tablo. Then while still holding the button down, re-connect the power cable, continue to hold the reset button for another 30 seconds, then release it.

Thank you got your reply. I repeated this sequence twice with no observable change.

Other ideas?

How do I send it for service/repair?

Did you try unplugging the power and then plugging it in again? I presume you did that already.