i was using a power bank on a raspberry 4 and it worked but now its not powering on at all no red light or anything i am using the official power supply on it
You might check the official power supply against a second Raspberry Pi 4, to see if the fault follows the power supply or the Raspberry Pi.
Power banks are notorious for not complying with specifications. Possible that a power bank delivered too high a voltage to the Raspberry Pi 4 USB-C power port, resulting in the destruction of the zener diode D1. This in turn may prevent the official power supply from starting up. If it were on my lab bench, I’d test D1, and test the voltage on TP1, TP2, and TP3. As per the schematic diagram.
is there any other way to fix it or power it as i cant test the zener diode as i dont have a multimeter to test voltage.
Apart from damaged Pi or failed power supply. there’s nothing else I can think of as the cause. You or anyone else would need tools and skills to fix this. If you can’t get those, the next best thing is to get another Pi or power supply, depending on which of the two isn’t working.
I strongly suggest not using the power bank again in the same way, without careful testing of the power bank and cable with multimeter. There’s a design feature of the Raspberry Pi 4 that makes using it with other USB-C power sources difficult. The feature is well-known though, and the documentation does say to use the official power supply.
If you got your Raspberry Pi 4 from Little Bird, give them a call and ask them if they have any ideas. Remember to say you think you killed it. Never know, they might have a used one up their sleeve. There’s also eBay.
thanks. i checked the power supply i was using and it still works, i just find it weird that the power bank works than i move the pi and plug it in and nothing happens.
checked the power supply i was using and it still works,
Great. That means the fault is most likely in the Raspberry Pi 4.
i just find it weird that the power bank works than i move the pi and plug it in and nothing happens.
Thanks, but I don’t find it strange. Something has permanently happened to the Raspberry Pi to stop it working. It was working before, and it isn’t now. You said you connected it to a power bank. There’s this known design feature of the Raspberry Pi 4 that makes connecting it to higher voltage cause permanent damage. The damage would be to the Zener diode D1, which will have become hot and exceeded absolute maximum temperature, resulting in failure. That failure could be a lowering of the zener voltage, and if so connecting the official power supply now could cause the official power supply to safely shut down as if it was short circuited.
It is easily proven using test gear. Find someone you know with the skills to have a look into it, in order to disprove my theory. I’m happy to be proved wrong, but from the information available there’s no other obvious cause.
If you’d like a non-obvious cause, there’s a possibility of ESD in your handling the Raspberry Pi 4 that could also cause this kind of symptom.
It is also possible that ESD happened before the Raspberry Pi 4 got to you, and the several cycles of power widened the damage until it stopped working. ESD rarely causes an immediate failure.
Hope that helps!