Faaark! Exactly the same thing here, only it only one motor dead.
After installing the Kit, I get er05 or er06 depending on the location of the build platform. The switch is working and has continuity right through to the main board.
The instructions should tell you to disconnect the stepper motors before moving the platform and head.
This is terrible! I think Ultimaker should accept responsibility for the omission.
When simply moving the stage, I measured 16 volts peak to peak across the motor!
Theres a video here:
Looks like the the A4988 ic has no protection for voltage coming back from the motor.
I'd say there is a very real risk of blowing up the motor driver ic's when moving the motors.
Senior Technician (EAS) (NZCE)
Departmental Health and Safety Officer
Department of Psychology, University of Otago
Te Tari Whakamātau Hinekaro, Te Whare Wānanga o Otāgo
Godard Laboratories, Level 2, 95a Union Plc East
PO Box 56, Dunedin 9054, NEW ZEALAND
Tel 64 3 479 7668 Fax 64 3 479 8335