Before sending the replacement chip, I’ve double checked that it is getting recognized via USB and that it can be programmed with sketches. It’s expected for USB to attempt to recognize the hardware if the B button is held down while powering on the system, so it enters the bootloader mode.
Further steps to debug the issue:
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Take a good look at the marked areas: USB Device Not Recognised - #5 by Giedrius, see if there’s anything wrong at all, you may want to double check whether the traces reach their destinations using a multimeter.
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Use a different USB cable.
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Try connecting to another computer.
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Try connecting through a USB hub (or connect directly to the PC, if you used USB hub before)