Raspberry Pi 5 Not Booting After Installing New OS via Raspberry Pi Imager

Hi everyone,

I just got a Raspberry Pi 5 and installed a new OS using the official Raspberry Pi Imager. The flashing process to the microSD card completed successfully, but after inserting it into the Pi and powering it on, it doesn’t seem to boot properly.

Here’s what happens:

  • The red power LED turns on and stays on.
  • The green LED lights up for 3–5 seconds, then turns off, leaving only the red LED on.
  • Pressing the power button makes the green LED blink once, but nothing else happens.
  • There is no display output to the monitor (screen stays black).

I’m a complete beginner and not sure where to start troubleshooting. Has anyone experienced this or know what might be causing it?

Additional info:

  • Raspberry Pi 5
  • OS installed: Raspberry Pi OS 64-bit
  • I’ve already tried reformatting the SD card and reinstalling the OS, but the issue persists
  • I’m using the official 27W USB-C Raspberry Pi power adapter

Any help would be greatly appreciated. Thanks in advance!

If you remove the SD Card and power up the Pi, do you see anything on the monitor?
If you have another spare SD Card, image it and try again.

Thanks for the suggestion.

I’ve already tried the following steps based on some troubleshooting guides:

  1. Powered the Raspberry Pi 5 without the SD card – the red LED stays on, and there is no display output at all.
  2. Tried different microSD cards, flashed with a fresh image of Raspberry Pi OS (64-bit) using Raspberry Pi Imager – same result:
  • Red LED stays on
  • Green LED lights up for 3–5 seconds, then turns off
  • Pressing the power button only makes the green LED blink once
  1. Tried a different monitor and HDMI cable, including using HDMI0 port – still no output
  2. Reflashed the bootloader using the official Raspberry Pi 5 recovery image on a FAT32-formatted SD card (with the recovery.img) – the green LED blinks fast as expected during bootloader recovery, but afterward, the board still won’t boot any OS images
  3. I’m using the official 27W USB-C Raspberry Pi power supply, so power should not be an issue

At this point, I’m not sure if this is a hardware issue or if I’m missing something. Are there any additional steps I can try to verify if the board is functional?

You could try to image to an USB-stick and try the stick instead of the SD-card. This is to rule out that the SD-card reader has a problem. Note, it should be a spare stick, the imager will probably destroy the whole content.

Strangely, the LED “pattern” you see is not documented: https://www.raspberrypi.com/documentation/computers/configuration.html#led-warning-flash-codes so this might also be a hint that the Pi firmware does not even have a chance to run.

And btw: for a “complete beginner” you already gave very good and complete information in your post, great!

If it’s in a case I would remove it. And remove anything connected to the GPIO Header. Maybe even unplug the keyboard mouse. HDMI 0 would be the Port I would use. Do you have a spare Power Supply? Even a Pi 4 PS would do for testing.

Thanks again for the suggestion!

I actually already tried booting from a USB stick using the same Raspberry Pi OS image (flashed with Imager), just to rule out SD card or card reader issues — but unfortunately, the result is exactly the same:

  • Red LED stays on
  • Green LED turns on for about 3–5 seconds, then turns off
  • Pressing the power button just blinks the green LED once

As you mentioned, the LED behavior I’m seeing doesn’t match any documented boot patterns in the official list:
https://www.raspberrypi.com/documentation/computers/configuration.html#led-warning-flash-codes

That’s exactly why I’m confused — it seems like the Pi doesn’t even reach the stage where the firmware can run properly, which makes it really hard to diagnose.

Any other ideas I can try? I’m open to digging deeper if there’s a way to check early-stage boot or hardware status.

Thanks for the suggestion!

Yes, I’ve already tried removing everything, including:

  • The case (I’m running it completely open now)
  • All peripherals — no keyboard, no mouse, no USB devices
  • Nothing connected to the GPIO header
  • I even disconnected the HDMI cable, so it’s only powered via USB-C with no other connections at all

Still, the behavior is exactly the same:

  • Red LED stays on
  • Green LED comes on for a few seconds, then turns off
  • Pressing the power button just blinks the green LED once

Unfortunately, I don’t have a spare power supply at the moment, but I’m using the official 27W Raspberry Pi PSU, which should be more than sufficient.

Let me know if there’s anything else I should try — I really appreciate the help!

Assuming, it’s not defective. ;)

If you bought from Pimoroni, drop them a note with a link to this thread. This sounds like a hardware problem.

Thanks for the tip!

Unfortunately, I didn’t buy it from Pimoroni, I got it from a local seller here in my country, and sadly, the warranty period has already expired, so I’m not able to request a replacement or return the unit.

That’s why I’m trying to troubleshoot as much as I can myself before giving up on it.
If there are any other ideas I could try to confirm whether this is truly a hardware issue, I’d really appreciate the help.

Update: Behavior Changed Slightly After Using Raspberry Pi Imager 1.9.5

Hi, just a quick update.

I tried flashing the OS again using Raspberry Pi Imager version 1.9.5 as suggested. After that, the behavior of the LEDs has slightly changed compared to before:

  • The red LED now turns on for 3–5 seconds, then
  • The green LED turns on for 1–2 seconds, then turns off
  • When I press the power button, the green LED lights up again for 1–2 seconds, then goes off

However, the Pi still doesn’t boot and there’s no output on the display.

Does this new LED pattern give any more clues about what could be going wrong?
Could it mean the Pi is at least trying to boot now, or is this still a sign of early-stage failure?

Thanks again for any insights!

Have a look at this, might help?
STICKY: Is your Pi not booting? (The Boot Problems Sticky) - Raspberry Pi Forums

Do you have a multi-meter / volt meter?
If yes I would carefully measure the 5V and 3.3V pins on the GPIO header. I’m thinking you probably have lost the 3.3V, a PMIC failure. Either that or your Power Supply is faulty.

It might be worth looking for, downloading, and using a different version of the Raspberry Pi Imager. Especially if your using the Windows version.

Pull/Remove/1.9.4 version of Pi Imager off the website. - Raspberry Pi Forums

And if you try that, I’d try another firmware recovery / reflash.