If your Raspberry Pi displays a black screen (sometimes with text) or a solid rainbow screen on startup, and the LED ring stays off and RFID tags don’t respond, this typically means the device cannot boot properly. The most common cause is a corrupted or unreadable USB stick or SD card.
How to Fix the Issue
Restart the cell
Use the following link to restart the cell: How to restart a cell.
If the issue persists after restarting, continue to the next step.Reflash the USB Stick or SD Card
If restarting didn't help, the storage device is likely corrupted and must be reflashed with a new image. Follow this guide to reflash your USB stick or SD card: How to reflash the USB stick or SD card.