People usually use
ssh or serial console for login when there is no monitor. If there is a monitor, but the GUI itself is the only problem, then you should be able to use the keybinding “
CTRL-ALT-F2” to reach a text-only terminal on the monitor (GUI and text are different drivers).
The green light should go on and stay on. Not having peripherals power up could be due to a number of different possibilities. Do note that a 2A supply is somewhat minimal, and would be a problem if the computing load goes up, but I doubt a keyboard or mouse would care (keyboard and mouse don’t consume much power).
If the SD card content is the wrong version for the QSPI content, then you either have to flash the Nano to the version compatible with the SD card, or flash the SD card to a version compatible with the QSPI content. The Nano models using the SD card do not put the boot content on the SD card. Earlier releases put differing amounts of content into QSPI memory (which is on the Nano module) during flash, and the earlier QSPI content is not compatible with newer SD card images.
Your best bet is to flash the Nano itself with the release version which produced the SD card image. This is how you are guaranteed that the two match. Flashing is the only way one would update QSPI content.