I tried powering it on without the sd card and I got a single solid red pwr led.DougieLawson wrote: ↑Mon Jul 29, 2019 12:00 pmPull the SDCard. Power on. Does it do the same thing? Does any part of your RPi get too hot to touch very quickly? Have you been abusing GPIO pins?
Can you measure the voltage between Pin#1 & GND (use the case of the USB or ethernet to avoid shorting pins)? Can you do the same for Pin#2 (or Pin#4)?
You may have had the spontaneous sudden death of your PMIC chip - the repair costs £35, but you'll get the bonus of an upgrade from RPi3B+ to RPi4B1GB for that price.
How did you connect those?
GPIO -> Led +Burngate wrote: ↑Mon Jul 29, 2019 5:50 pmHow did you connect those?
Taking too much current from a GPIO, or letting more than 3v3 near a GPIO can damage the SoC
https://www.raspberrypi.org/forums/view ... 28&t=58151 is useful, if you haven't already read it.
You need a resistor between the GPIO and the LED (or between the LED and GND) to limit the current.
3V3 -> Buzzer VCC
GND -> Buzzer GND
GPIO -> Buzzer Input
Well RIP my raspberry pi. I did put a 51Ω resistor in the circuit. I guess that's not enough to limit the current to a safe level.Burngate wrote: ↑Tue Jul 30, 2019 9:08 amYou need a resistor between the GPIO and the LED (or between the LED and GND) to limit the current.
Too much current can damage the GPIO circuitry inside the SoC, and that damage can spread.
LEDs are not straight-forward devices - up to a certain voltage, almost no current passes, but above that voltage they act like very low resistances, so very large currents can pass.
This may be the cause of your problem - or it may not, depending on the actual current your particular LED took
A GPIO can safely provide 16mA.
Thanks. Good to know.