I was running a Pi 3b model from an "insecure" power source, aka unknown car radio USB, no idea how many amps it gives. but the lightning symbol appeared on the HDMI screen, then the screen flicked a couple of times and I pulled the power after 1 minutes or so. This was the last time with the system operating. Red LED is on, Orange LED is blinking a couple times and then stops. Also, I tried different power supplies with 1-2,5A and different cables.

Now it seems like the Pi is over overheating during boot. SSH isn't working ever, although I'm not sure about it, because the Ethernet port is blinking some times.

What can I do, to get it back online?

2 Answers 2


I can't see that too low a positive voltage could damage the Pi. An over voltage could.

Getting hot very fast is a symptom of a failed or failing Pi, typically caused by an over voltage.

Under voltage may lead to a corrupted SD card. It's a good idea to write a new operating system image to the card and see if that works.

  • 1
    can an car radio give overvoltage and does the lightning symbol also indicate overvoltage? I reinstalled raspian on 2 different cards without booting success yet.
    – user120435
    May 31, 2020 at 9:41
  • 1
    The lightning symbol indicates under voltage. The only over voltage warning is a failed Pi. Perhaps work through raspberrypi.org/forums/viewtopic.php?t=58151
    – joan
    May 31, 2020 at 9:44
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    Where could the over voltage come from? From HDMI? From car radio?
    – user120435
    May 31, 2020 at 12:51

System won't let me comment... so I'm providing my comments within the answer section, sorry...

1) why do you suspect under voltage?
2) without know everything you've tried, take a known working power supply, if the pi doesn't work with that, and the last time it sort of worked was when plugged into the car radio USB, I'd say check the voltage of the car radio USB.
The on board voltage regulator of the car radio USB is supposed to limit it to 5.1 volts or so, if that is not the case and it's too high, you may have fried the pi.

3) If the voltage is too low, I can't see how that would damage the pi, it just won't work right until you supply it with sufficient power.

4) the pi needs sufficient current, it will draw what it needs from the power supply, if the source will not deliver that current, the voltage will drop and eventually you may blow a fuse in the power supply.


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