An authorized service center can boot load a new factory image and return it to service. But I am puzzled the ADB method is not working. Even if someone had loaded HPlus, H3 or H520 firmware on it, it should respond to the ADB command and let you do a factory reset.Gotcha. Yea, I tried all of those suggestions before I posted. It's not the cable or battery unfortunately. There's got to be some way to get past the security pattern..
Do you have another ST16 or ST16S controller available to see if they will respond to ADB commands using your equipment? (You don't have to actually finish the reset. You can turn the switch off and pull the battery after it shows the android recovery screen.)