I thought it would be simple to test the new USB-based SD card reader I bought, but it ended up being a multifactorial nightmare. So far I've learned: - My Thinkpad T520 has flaky USB ports, but the T420 is OK. - Almost all of my SD and MicroSD cards are corrupted. - I have exactly one MicroSD card that works at all in both the new and old readers. And then some mysteries: - Using the new reader, after using "safely remove", it repowers spontaneously. [EDIT: But doesn't remount, at least.] - Using an SD adapter, the working MicroSD card mounts read-only in the old reader, and isn't recognized at all in the new reader. So, does the new reader work? Who fucking knows!