Rainbow Screen (No Boot)
Raspberry Pi Single-Board Computer
Severity: CriticalWhat Does This Error Mean?
The rainbow screen (a square of colours in the top-left corner) means the GPU started but the kernel failed to load. This usually means the SD card is missing, empty, corrupted, or has an incompatible OS image. Re-flash the SD card with Raspberry Pi Imager.
Affected Models
- Raspberry Pi 5
- Raspberry Pi 4B
- Raspberry Pi 3B+
- Raspberry Pi Zero 2 W
- Raspberry Pi 400
Common Causes
- SD card not inserted or not properly seated
- SD card not flashed — it is blank or has the wrong format
- OS image is for a different Pi model
- SD card corrupted — kernel files damaged
- start.elf or kernel.img files missing or corrupted
How to Fix It
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Check that the SD card is properly inserted.
Push the SD card firmly into the slot — it should click into place. On the Pi 5 and Pi 4, the slot is on the bottom of the board.
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Re-flash the SD card using Raspberry Pi Imager.
Download Raspberry Pi Imager, select your Pi model and OS, and flash. The Imager handles formatting and downloading automatically.
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Make sure the OS image matches your Pi model.
Pi 5 requires a newer image than older Pis. Old images may not have Pi 5 support. Always select your exact model in Raspberry Pi Imager.
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Try a different SD card.
If the rainbow screen persists with a freshly flashed card, the card itself may be faulty. Try a different card.
Frequently Asked Questions
What does the rainbow screen actually mean?
The rainbow square is generated by the GPU firmware as a test pattern. It appears briefly during normal boot (then disappears). If it stays, the GPU loaded successfully but the Linux kernel did not.
My Pi shows a solid red light but no display output. Is this different?
A red light with no display usually means the Pi has power but cannot read the SD card at all. The SD card may not be inserted, may be blank, or may be dead.