Formatting USB stick - ALCOR chip AU6998N onboard


Apr 29, 2012
Hello to everybody,

I'm not really an expert about USB devices and chips installed inside them but ...

The chip seems to be an ALCOR AU6998N.

My problem was about a read-only filesystem on my stick. ( I don't really know why but maybe it was caused by a wrong un-plug step ).

When I try to format my USB device an error appear giving me the information that the device is "write-protected" .

So, when I create, for a few seconds, a bridge on the chip - right side ( more or less bridging two pins, one-near-the-other, in the middle of the right side ) I can unlock the situation and the filesystem appear to be writeable ... Infact the formatting operation starts.

But, when the format seems to be finished ( the bar is completely blue ) an error comes on video telling me that the operation can't be terminated correctly.

For this reason I would like to know if somobody knows something about this problem and if somebody found a solution, maybe creating one more bridge on pins.


Jun 13, 2006
Actually this symptom is from 1 of 2 scenarios:

1. whoever you got the drive from and pre-programmed marketing material on the drive. In doing so, to make sure you always have their marketing material, they flipped the write protect switch (programmatic, not physical switch).

2. (most likely scenario) the drive has worn out or gone bad. When this happens the USB controller puts the medium in a write protect state to insure you can recover some data. The only way to get around this is to reprogram the controller, which can only be done with manufacturing software tools. You may have bypassed it a little in bridging the pins, allowing for more V to get to the NAND, but it's not an actual fix.

Either way, I think the USB drive needs to be replaced
Nothing to lose, so try this:

.. Open a dos command window WITH run with admistrator privlage. then type the following cmds.
- Diskpart Starts program Do Not type the - (ie diskpart> List disk then enter key)
- LIST DISK (shows all disk, look for Disk Number of the Drive (Your USB drive)
- SELECT DISK X (For X insert USB drive Number)
- DETAIL DISK (Detailed information of the disk that has the focus This will show if you have selected the correct drive.)
- CLEAN (One of the most practical and most dangerous: it removes at once all the partitions on the selected disk.)
Note for the next two do NOT use the size=n)
- CREATE PARTITION EXTENDED (Creates an extended partition on the current drive. After the partition has been created, the focus automatically shifts to the new partition.)
- CREATE PARTITION LOGICAL (Creates a logical drive in the extended partition. After the partition has been created, the focus automatically shifts to the new logical drive.)
- EXIT (Quits DISKPART and returns to the command prompt classic)

You should now be able to format the drive (WITH the correct space) using windows
Ref [...] 172499.htm

I used the above to "repair" a problem 4 gig thumbdrive.