SanDisk Ultra 32GB (VID:PID 0781:558A) stuck in hardware write-protect — controller shows "Unknown" in ChipGenius, looking for exact controller ID / recovery options
Hey all troubleshooting a dead SanDisk Ultra 32GB and hit a wall on controller identification. Data doesn't matter, I'm fine with destructive recovery attempts. Posting full diagnostics in case anyone's dealt with this exact chip.
Drive:
- SanDisk Ultra, 32GB nominal / 28.6 GiB usable
- VID:PID = 0781:558A
- Serial: 03018817100220090548
- Marking on casing: BM201067713W
- USB 3.x capable, currently negotiating at 480 Mbps (USB 2.0 speed)
Symptom:
Kernel and every tool I've tried report the device as hardware write-protected, not just filesystem RO:
sd 2:0:0:0: [sdb] Write Protect is on
sd 2:0:0:0: [sdb] Mode Sense: 43 00 80 00
lsblk shows RO=1. blockdev --getro returns 1. hdparm -r0 /dev/sdb is rejected outright — reports back "readonly = 1 (on)" even after the "set" command. This is coming from the controller's Mode Sense response (byte 0x80), not the OS.
What I've ruled out:
- Not a filesystem-level flag — chmod/mount -o rw/fsck won't touch this, the SCSI layer itself is refusing writes
- sg_modes -p 0x1a → "invalid field in cdb," page not supported
- sg_readcap -l → fails with "Read-only file system"
The actual problem — controller ID:
This is where I'm stuck. Genuine SanDisk Ultra drives on this VID:PID apparently use SanDisk's own in-house controller, not a merchant chip (Phison/Alcor/SMI), so the usual identification tools come back empty. From what I've found searching around, ChipGenius and Flash Drive Info Extractor report "Controller: Unknown" for this exact VID:PID on other people's genuine units too — not just mine.
What I'm hoping someone can help with:
Has anyone actually identified the physical controller marking on a genuine SanDisk Ultra 558A PCB (not a rebadged/counterfeit one)? Willing to open the case and post a photo of the die/chip marking.
Is there any known MPTool or recovery utility that works on SanDisk in-house silicon, even semi-official/leaked? I know Phison/Alcor/SMI all have community tools — has anyone found an equivalent for SanDisk's own controllers?
Given the "Write Protect is on" bit is coming from Mode Sense and won't clear via hdparm/blockdev, is this consistent with NAND spare-block exhaustion putting the FTL into failsafe, or could it be something else at the controller level I'm not considering?
Drive is fully expendable — happy to try destructive low-level commands, vendor-specific SCSI opcodes, JTAG/UART probing, whatever. Just trying to figure out if there's a real path forward before I write it off as dead silicon.