Tri-State Data Recovery is your best choice for data recovery on nearly all brands of USB flash memory sticks.
Did you know that usb flash drives have a shelf life? The data on the chip starts becoming corrupted after so many read/write cycles. The average life-span of a USB or SSD is about 5-6 years. This chip must be removed in most cases, decoded with special equipment which could take some time depending on encryption. A common system occurs when windows will ask if you want to format the drive and will no longer allow you to access the data. DO NOT format the drive. Physical damage of the usb stick is very common, as well. If the USB connector has broken off, the data is still recoverable.
Did you know that the data is stored on a chip on the circuit board called NAND?