My new MX535 board is based on Quick Start RevB and use a new PMIC MC34709. I checked all voltages are ok, the 24MHz works too, but I set the boot mode to serial download, my PC always get the unknow device. I found when I send a reset a this time, the unknow USB device changes to "SE BLANK RITA" device, and no driver. Does anybody know what's wrong with it? What is SE BLANK RITA device? It looks like the MX535 works a little, but the USB device should be "Bulk IO Device".