My raspberry pi 3+ is showing undervoltage warning. I know this is a common issue and I've done a fair bit of trouble shooting, so please keep reading.
At first, I tried powering my raspberry pi with phone chargers rated for 5V at 3A. This is when I first got the low voltage warnings.
Since many forum posts suggest that phone chargers are not suitable power supplies (even if they have the appropriate power ratings, and I do not have an official Rpi charger on hand) I tried powering the the Pi from an old ATX power supply. (Soldered a microUSB connecor to the 5V lines of the power supply.. The ATX power supply is rated at 20A for the 5V line. Far in excess of what the Pi will use)
The low voltage warnings still recurred.
Then I thought it was an issue with the micro USB cable OR the Rpi's microUSB connector. So I tried bypassing the micro USB connector and powering the raspberry pi directly through it's 5V pins.
But.. I still keep getting the low voltage warnings.
To be more specific, I think I am getting what's called a "brownout".
As decribed here, the red LED turns on briefly at boot and then stays off. - apparently this means that a brownout sensor has been triggered.
vcgencmd get_throttled command and the
dmesg command, I was able to confirm that CPU is indeed being throttled due to low voltage and the low voltage warning had shown up in the kernel logs.
So.. what else can I try? Is there something wrong with the Pi? Is there something wrong with the OS? (I'm using OSMC). Am I left with no choice but to try the official power supply? They are quite expensive in the local currency :(