USB forcely turn write protection off from a hardware lock

Question

I have a USB-flash device (SanDisk SDCZ33 BM120423519D) with no hardware switch, which is stuck in readonly mode:

# hdparm /dev/sdf

/dev/sdf:
SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 14 00 00 00 00 20 00 00 0000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 multcount     =  0 (off)
 readonly      =  1 (on)
 readahead     = 256 (on)
 geometry      = 30532/64/32, sectors = 62530624, start = 0

I've tried to clear its r/o mode with:

# hdparm -r0 /dev/sdf

Then tried to format it with gparted, but it fails with error messages:

The files system is availabe only for read

After reinstertion the flash device is still stucked in the r/o mode.

The problem with r/o mode is risen after the one of halts of the host device (Raspberry PI). So the question is how to REALLY clear the readonly flag?

Answer 1

Well the flash has been simply locked by its internal mechanisma, and the manufacturer of the flash just replaced it. So step-by-step navigator follows:

1. I wrote the same letter to the company's support and got the answer in which they said that:

   Write protection happens to prevent data loss from a potential fault. We recommend to backup your data immediately.

   And they gave me a form to fill it in, in order to create the product return and replace with the similar one:

   • Place of purchase
   • Date of purchase (MM/DD/YYYY)
   • Do you see the letter "R" or the word "Refurb/Refurbished" at the back of the > product?
   • How was the product packaged at the time of purchase?
   • Please also provide your phone number (we use this only for follow up on your case should it be needed and do not use it for other purposes)
   • Physical damage (Yes/No)
   • Complete address (no P.O Box please)

   Since a replacement is required, you may take it back to your place of purchase for faster service. SanDisk is happy to replace your product as well.

2. Then I've sent requested data by email to the manufacturer. The data are the place of purchase, date of purchase, presence of letter "R" or the word "Refurb/Refurbished" at the back of the product, kind of the product package at the time of purchase, my phone number, Presense of physical damage, and my complete address. And then they proposed me to do the following steps:

   • Send your "Manyfactorer" device(s) to the address provided below via any carrier with a tracking number for proof of delivery.
   • Use a regular padded tamper proof envelope.
   • Please print this approval email (this page only) and put it in the envelope along with your SanDisk device.
   • Please DO NOT send any accessories like headphones, cables, plastic cases, adapters etc.
   • Write your RMA number ( RXxxxxxxx ) on the envelope.

3. So then I've moved the properly packed device to nearest depot (I've asked about it from manufacturer). In my case it was in Moscow. Russia. There was two variants to move the device to manufacturer: to bring it physycally, or to send via post. I've selected the first one. And next, after a few weeks they send me pack similar device that works. The conclusion is: don't hesistate to write to support.