Write protected micro SD cards?
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| 1 | In a recent auction (traditional, not Trademe) I took a punt on a "box of electronics) for $20. Ended being a bunch of Raspberry Pis and nice mini PCs which I was stoked about. Weird thing is all the Pi's seem to have some form of write protection on the Sandisk (ultra) micro SD cards. I can power them up and they all work fine. They must have formed part of an in-store advertising/ information system for a Westpac bank branch, they play music and show Westpac advertising videos, home loan rates etc. I can SSH into them and I can pull up their web server and if I mount the cards in Linux I can explore the entire file system, which is all totally no use to me. What I cannot do is write to the SD cards at all. I've tried every tool I can think of; Gparted will successful delete all partitions without error only for them to promptly reappear undamaged. Disks will do the same. On Windows diskpart will happily clear and delete partitions with no errors but again the cards emerge unscathed. Trying to format any partion will fail every time. Balena etcher will go through the entire imaging process and then happily tell me the task failed. Raspberry Pi imager just wont complete the imaging process. I'll throw every file system destroying tool I can find at these cards, put them back into the Raspberry Pi and they'll just boot up like I haven't even touched them. At this point I've wasted way more time than the cards are worth, but I'm more intrigued than anything. I wonder if its because they maybe were attached to a network inside a bank and had to be read only devices for security purposes? But I've never heard of such persistent write protection on micro SD cards. Any ideas? Edited by oclaf at 3:47 pm, Fri 14 May oclaf - 2021-05-14 15:47:00 |
| 2 | maybe this helps - don't know of any other way to lock them. solution 3 is probably referring to the phones disk encryption king1 - 2021-05-14 15:54:00 |
| 3 | king1 wrote:
Yeah, I stumbled across that too. Doesn't seem to be relevant. I put one in my phone. It would only interact with the fat boot partition and didn't want to format it. The cards have no encryption so far as I can tell. Edited by oclaf at 4:09 pm, Fri 14 May oclaf - 2021-05-14 16:09:00 |
| 4 | maybe have a look at the partition layout, might be something weird about the layout used that's upsetting the partition managers. would be interesting to try a drive wiping tool on one as well, see if it likes a bunch of 0s and 1s written to it. I use partition wizard home edition for that, sometimes active@ killdisk Edited by king1 at 4:43 pm, Fri 14 May king1 - 2021-05-14 16:42:00 |
| 5 | You wrote: "No, its not the write protect tab on the SD card adapter" Dumb question: Is this the little slide at the side which physcially moves from 'locked' to 'unlocked' on my SD cards? Answer: Yup, I just looked myself! ETA: Sorry, wish I could help. Edited by hazelnut2 at 4:53 pm, Fri 14 May hazelnut2 - 2021-05-14 16:44:00 |
| 6 | Damaged, permanently write protected. No fix, its a thing with some microSD. Had it happen, seen it happen, researched it. Permanent. ronaldo8 - 2021-05-14 18:11:00 |
| 7 | ronaldo8 wrote:
Hmm I never knew that they can fail read only. Apparently it's not uncommon for Raspberry Pi's to corrupt the SD cards rendering them permanently read only. Strange that I have a whole bunch that have gone that way, but I guess that's the best explanation. Now I really feel bad that I wasted a whole day of my life trying to resurrect less than $50 worth of dead SD cards. oclaf - 2021-05-14 19:54:00 |
| 8 | That's OK, SD cards have come down in price a lot recently. tygertung - 2021-05-14 21:49:00 |
