Hi, My almost complete MB-6582 (feedback pots missing) is having a strange issue where all LEDs light up in checkerboard pattern, no buttons or encoders respond. Control surface is ok, I tested it according to the instructions here:  http://www.midibox.org/dokuwiki/doku.php?id=control_surface_troubleshooting The HC165 (which I understand manage the buttons and encoders) have ~4.84V at the 5V pin:  http://midibox.org/forums/topic/21318-quick-n-dirty-voltage-test-chart-for-mb-