12 Replies Latest reply on Sep 9, 2020 1:17 AM by willh83

    Pi3 shows yellow lightning bolt with official power supply

    chaozz

      I got a Raspberry Pi 3 from TinyDeals to review on my Youtube channel. However, when I run Raspbarian (I tried two different SD cards) or RetroPie I get a yellow lightning bolt in the top right corner. I understand this means "undervoltage".

       

      I am using the official Raspberry power supply (I have two, brand new) and tried different phone chargers all with the same result. I have also tried different SD cards and don't have anything plugged into the USB ports.

       

      Is my unit broken?

       

      PS: I am also a bit disappointed I won't be able to do a review of the Pi, since I won't be able to get warranty on this device (and bought a case and power supply for nothing).

        • Re: Pi3 shows yellow lightning bolt with official power supply
          Roger Wolff

          Yes, the yellow lightning bolt means "undervoltage". Normally "its right about it", i.e. when it says it's undervolting, that is usually the case.

           

          The good news is that the pi itself will work just fine (and within spec) down to about 3.3V on the 5V input rails. The bad news is that HDMI devices that expect to be powered with 5V from the PI like the HDMI->VGA adapter that I have, will not be happy. Similarly, USB devices that are bus-powered will usually not like this situation.

           

          As you have an HDMI screen (you see the yellow bolt), and don't need an HDMI->VGA adapter, and you can use a powered USB hub for USB devices that you need, the pi can still be tested.

           

          But.... Before you go blaming the pi... I would recommend you test if the pi is "lying" or not. What is your 5V powersupply delivering? On the GPIO connector, nearest the corner, you find a pin with 5V (pin2). The pin along the edge of the PCB is another 5V pin (pin4). The next one is "GND". So get out a multimeter and measure it. Are you getting less than 4.75V ? Then the pi is right when complaining about low voltage level....

          3 of 3 people found this helpful
          • Re: Pi3 shows yellow lightning bolt with official power supply
            jasonelmore

            I wonder if increasing the Over_voltage= setting in the Raspberry Pi 3 Config file would have the effect of increasing the voltage available to these chips, therefor getting rid of the lightning bolt.

             

            I would be very interested to know the relationship between overclock, lightning bolt, and the over_voltage setting.

             

            On a Overclocked Pi, could I keep increasing the over_voltage setting until it disappears?  Or is something fundamentally wrong with my overclock?

             

            Official 2.5A canakit powersupply on a pi3 running conservative Overclock settings in a Nespi Case:

            total_mem=1024
            arm_freq=1320
            gpu_freq=510
            core_freq=510
            sdram_freq=500
            sdram_schmoo=0x02000020
            over_voltage_sdram_p=6
            over_voltage_sdram_i=4
            over_voltage_sdram_c=4
            over_voltage=3
            sdram_over_voltage=2
            avoid_pwm_pll=1
            v3d_freq=510