I don't understand why after 4 Apple Repair Depot visits my MB Pro is STILL killing several USB FLASH and external hard drives a week. It has consistently done this since the day I bought it. I have fried a large variety of FLASH Memory sizes, shapes, through all USB ports and even through attached hubs. Once my mac does this to a USB device, it is no longer recognizable by any Mac or PC ever again. Unrecognized, it doesn't even leave an opportunity for Disk Utility to reformat, rewrite, perform first aid, verify...nothing. Third-party formatters don't work either. It also doesn't seem to matter what brand, size, or port I use. For a certain period the devices would become very hot and sometime actually melt into puddles of liquid plastic and metal. On the 4th depot dispatch for this issue they did replace the mother board USB ports and EVERYTHING ELSE but the display hard drive, and case. This stopped the heating and melting problem, but I'm still frying the devices and rendering them unrecognizable. Does anyone have ANY IDEA of what may be causing this? Is there anything I can do to stop or prevent it? Apple sure can't explain it much less fix it. This is a huge EXPENSIVE problem, and I can't seem to get past it, and I'm in an endless loop of sending in in for constant repairs. WHat can be done to stop or prevent this from happening? PS Any advice on how to resurrect this huge PILE of unrecognizable USB devices.