Sandisk Ultra USb 3.0 64Gb disappear from USB port after copy file half way. Using EaseUS Partition Master found some bad area and after many bad area appear, it dismount from USB port. Try to use format partition, delete partition all not successful.
What should I do? How can I mark the bad sector like harddisk for me to continue use it. Although it is life time warranty but troublesome to go for repair.
It sounds like the USB drive is starting to fail. If EaseUS is finding lots of bad areas and the drive disappears while copying, the flash memory or controller is probably damaged.
Unfortunately, USB flash drives don’t work like traditional hard drives, so you can’t simply mark the bad sectors and continue using the remaining space reliably. You can try chkdsk /r, but it won’t fix physically damaged flash memory.
I’d recommend copying any important files off the drive immediately and avoiding further formatting attempts. Since your SanDisk drive is covered by warranty, replacement is really the best option. Continuing to use it could result in more data loss.
