A Fault 27 message indicates the device is overheating. Please, disconnect all parts to the Z1 or Z2 (battery from the PowerShell, PowerShell from the machine, and unplug it from the wall). Allow the device to cool down in a shaded area below 80 degrees for a couple of hours. After letting the Z1/Z2 cool down, reassemble the parts to the Z1/Z2, and the fault should go away. If the Fault 27 does not disappear it will need to be submitted for a return.