I have 2 Raspberry Pi 4 model B's, 4gb of ram (meant to be identical).

I put the SD card in one and the power light is red and the other light is solid green (this is the one that is not working)

The other I put the same SD card into and it boots, screen lights up, keyboard works everything is fine.

The only factor to change is the Pi its self, can I fix this? What is the issue? How do I fix it?

This Pi has worked before, sometimes it boots, sometimes it does not. Have not managed to boot it in a few weeks however it powers up fine.


When the Pi sometimes boots and sometimes not, there can be numerous reasons for that:

  • A broken or unstable power supply. Swap the PSUs of both Pis and light them up to find out. You should also attach a USB multimeter to check the PSU's output voltage.
  • A broken PSU cable
  • Damaged pins in the SD card bay. You'll need a magnifier to check.
  • Problems with the Pi itself: Firmware fault, some electronic element broken, memory corrupt,… Attach your Pi to an HDMI monitor and look for error messages appearing on the screen.
  • The screen is black as the night, I get nothing at all. and the PSU cable is the same as the one that works (as in I only own 1 cable, I just change the Pi with all the same stuff, only the board changes in the set up)
    – user35453
    Dec 29 '19 at 18:55
  • This may mean that your Pi is broken. As you said, the green LED is on all the time. This could be a sign for a serious issue. :/
    – Neppomuk
    Dec 29 '19 at 22:57
  1. Check the power supply. This is the most common problem I've come across.
  2. Run memtester to check if you have a memory problem.

If that doesn't help maybe you should upgrade your

sudo rpi-update 

to update your firmware. This is shouldn't be needed under normal circumstances.

  • I am using the same power supply for both Pis (Im only changing the board, same SD card, same power supply, same monitor, same hdmi cable etc etc) Im going to need a UART for that rpi-update I assume?
    – user35453
    Dec 29 '19 at 18:51
  • I have now gotten it to the point where the Pi ACT is (the green one) occasionally flashes / flickers? does that mean hope?
    – user35453
    Dec 29 '19 at 19:15
  • another update, plugged the PI into my pc and the pc (eventually) saw it come up as bcm2711 boot
    – user35453
    Dec 29 '19 at 19:18
  • 1
    explain how one runs memtester or rpi-update (or anything) on a pi that doesn't boot? Dec 30 '19 at 3:07
  • Suggesting to use unstable software under development with rpi-update is not a good idea to fix a hardware problem.
    – Ingo
    Jan 6 '20 at 9:02

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