Poor connection to the printer's card reader, it's loose. I can read the contents of the SD card when I plug an extender into the printer, but if I remove the SD card and plug in another, it still shows the contents of the first card. I have to unplug and plug the power strip back in. There was a sticker on the box saying it was tested so I'm assuming it was sent back. This is my second card extender from two different companies. The first one didn't work at all unless I wiggled it in the printer and as soon as I let go of it it stopped working. It could be my printer's card reader, but it will read any micro SD card I insert. I do not know. I just gave up. FYI I'm trying this with Ender 3 v2.
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