I’ve searched this forum in vain for a similar problem. I had no problems before, but now when I plug my M250 into the USB port, nothing happens. The device doesn’t appear in Windows XP at all! It doesn’t matter whether it’s in MSC or MTP mode. The display on the player doesn’t show anything new. The little light on the USB hub doesn’t go on. Nothing happens!
I’m using the same short lead that came with the player. I updated the firmware to V4.1.08E. I’ve checked the USB port and it works fine with other devices.