If you see a rainbow screen when powering up your Raspberry Pi, it usually means the Pi has started the very early part of the boot process, but hasn’t moved on to loading the operating system yet. In most cases this is caused by the boot media (microSD/USB), display connection, or power.
🕒 1) Let it run for a few minutes (especially on first boot)
On a normal boot, the rainbow screen should only appear briefly. However, on the first boot of a freshly imaged card, it can take a little longer to move on (depending on the storage speed and setup).
We recommend leaving it powered on for up to 5 minutes. If it still hasn’t progressed, move on to the steps below.
✓ LED check: If the green ACT LED is flashing in a repeating pattern, note the pattern and compare it to the official LED flash codes: LED warning flash codes.
🖥️ 2) Check your HDMI connection and port
A “stuck” rainbow screen can sometimes be a display/handshake issue rather than a true boot failure.
- If your Raspberry Pi has more than one HDMI port (e.g. Pi 4 / Pi 5), make sure your primary display is connected to the port marked HDMI0.
- Check the monitor is set to the correct input.
- For troubleshooting, use one monitor only and connect it before powering on.
⚠️ Note: Raspberry Pi models do not output video over USB-C, so USB-C to HDMI adapters won’t work for display output.
💿 3) Re-image your microSD card
If the rainbow screen stays on indefinitely, the Pi often isn’t finding the boot files it needs — or the image on the card isn’t compatible with your model.
We recommend creating a fresh card using the official Raspberry Pi Imager. If you have the option, let the verify step complete.
If you’re reusing an older card/image from another Raspberry Pi, it’s best to re-image rather than trying to boot it “as-is”.
⚠️ Warning: Writing a new image will erase the contents of the microSD card. Back up anything important first.
💾 4) Check microSD card quality (and re-seat it)
Storage issues are a very common cause of boot problems. We recommend using a high-quality microSD card (ideally an A2-rated card) and ensuring it’s fully inserted.
- Power off and unplug the Pi, then remove and reinsert the microSD card firmly.
- If possible, test with a different known-good card to rule out a faulty/counterfeit card.
- If you’re unsure what to choose, official Raspberry Pi microSD cards are a solid option.
✓ Recommended: Browse our Raspberry Pi microSD cards here: Raspberry Pi SD cards.
🔌 5) Power supply (remove non-essential peripherals)
Unstable power can prevent the Pi from reliably reading the boot media, which can look like a stalled boot.
- We recommend using an official Raspberry Pi power supply for your model.
- Disconnect anything not required for boot (USB drives, HATs, cameras, etc.) and test with just: Pi + power + microSD + HDMI.
- If you have one available, try a different known-good power supply.
✓ Recommended: Official Raspberry Pi PSUs (including the Pi 5 27W USB-C PSU) are here: Raspberry Pi power supplies.
💡 6) Bootloader sanity check (Pi 4 / Pi 5)
On Raspberry Pi 4 and Raspberry Pi 5, the bootloader lives on the board. A quick check can help confirm whether the bootloader is running.
- Power off the Pi and unplug it.
- Remove the microSD card.
- Reconnect power. If the green ACT LED flashes a repeating 4-flash pattern, that’s expected (it indicates the Pi can’t find boot files) and suggests the bootloader is running.
⚠️ Note: If you see a different repeating flash pattern, compare it to the official LED warning table: LED warning flash codes.
🔍 7) More detailed troubleshooting
If you’ve tried the steps above and you’re still stuck on the rainbow screen, the Raspberry Pi forum has a long-running “Boot Problems” sticky thread covering common boot issues (including the rainbow screen).
✓ Helpful link:Raspberry Pi forum: The Boot Problems Sticky. If you’re asking for help, include your Pi model, power supply used, boot media type, and any ACT LED flash pattern.