I have an RPI4 (Buster) with SD Card for root storage as a home server. Recently I noticed that it does not boot up automatically after power outages. When the electricity is turned back, all lights are solid (red and green) and nothing happens. But re-connecting the power plug usually helps and RPI boots normally. I don't have any kind of buttons on my power supply, it's just a regular power supply plugged directly into a socket. At the moment, I'm not at the same location where RPI is set so I don't have any physical access to connect the display and see BIOS output when the problem is ongoing or perform other ways of in-place troubleshooting. But I have SSH access and can manage the system while it is running. I would be grateful for some ideas for where to look, but I would prefer not to make any critical modifications to the boot configuration because if it fails I will lose access completely.

  • Why it is normal? Obviously, this is an issue when RPI is being used as a server as it requires manual intervention and it's not reliable. If there is any particular problem, let's say corrupted FS, then how happens that one more reboot fixes it? Why RPI can't fix or ignore this automatically?
    – ihorc
    Commented Nov 25, 2022 at 13:15

1 Answer 1


I will take a SWAG: I have seen this many times over the years with many computers, it is the Power. Build a small circuit that detects power failure and when it comes on delay the pi from being powered for a few seconds. Without being there I can only assume that other appliances yours and others on your transformer have appliances that are coming back on especially units with motors and compressors for starters.

I have built a PCB that has a counter and a watchdog input. When the power comes on it powers the load, when it does not start batting the trigger it turns of for 8 seconds then starts over until it is getting patted.

  • Actually, I found a solution based on watchdogs and it should work out of the box with no external PCBs or additional hardware. Looks promising, haven't tested it yet. raspberrypi.stackexchange.com/a/113193/144452
    – ihorc
    Commented Nov 25, 2022 at 20:47
  • That is great, let us know how it works for you.
    – Gil
    Commented Nov 25, 2022 at 23:58
  • One thing about a watchdog is the processor must run code to enable it. Let us know how it works.
    – Gil
    Commented Dec 25, 2022 at 19:55
  • @ihorc, you should consider posting it as an answer Commented Dec 26, 2022 at 1:17
  • Yes, it works as expected with RuntimeWatchdogSec=15. However, when I additionaly set RebootWatchdogSec it stops working. So I ended up with one option only, no issues since then.
    – ihorc
    Commented Dec 28, 2022 at 18:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.