Okay, seems like I was too quick when saying that the secure erase did not work. Obviously, the partition table was still cached when I called fdisk, because when I tried the whole procedure again, rebooting without reading back the disk image with dd and the disk turned out to be empty. I also checked out that ADATA SSD toolbox on Windows as you suggested and used the secure-erase function in the tool. No new insights, though, the tool is pretty vague just showing a full green bar, that the disk is okay and all there's a bunch of tests I can run that just tell me everything is fine in the end without going into details. I tried to update the firmware of the SSD, but the usb image provided in the tool fails to boot, not that I think a firmware update would reduce the error count anyway. So it seems it's stuck at 7 bad sectors currently and the disk is still fine. I don't like it, because at some point I will have to decide what to do with the new SSD, use it in another computer most likely, I can't keep it as spare just in case the bad sector count increases indefinitely.rene wrote: ⤴Sat Apr 14, 2018 2:19 pmBut can not, then, say anything sensible at this point. Might be cause for a forum-wide poll/call for experience with a non-zeroing secure erase. And/or: can you hook up the old SSD as an extra and run the ADATA tool from the Windows 7 partition on the new one against the old SSD? It mentioned to also support secure erase and it would in any case be interesting to see if it has something to say about the old SSD.
As for the HDD, I got a replacement on warranty.