Rasp 3 B+ No Boot
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Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
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- JWas
- Posts: 4
- Joined: Sun Jul 15, 2018 1:42 pm
Rasp 3 B+ No Boot
Hello, I'm using new SD cards and the current version (June 2018 - kernel 4.14) of Raspbian Stretch. No activity light, only red power solid. Do I need to test GPIO voltages? Thanks
- adafruit_support_carter
- Posts: 29469
- Joined: Tue Nov 29, 2016 2:45 pm
Re: Rasp 3 B+ No Boot
If you can, please do. Check the voltage on the 5V and 3.3V pins:Do I need to test GPIO voltages?
https://pinout.xyz/
Also, please post a photo of the front and back of the board.
- JWas
- Posts: 4
- Joined: Sun Jul 15, 2018 1:42 pm
Re: Rasp 3 B+ No Boot
Here's the pics. I can test when I can home on power pins.
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- adafruit_support_carter
- Posts: 29469
- Joined: Tue Nov 29, 2016 2:45 pm
Re: Rasp 3 B+ No Boot
Were you able to measure the voltage on the GPIO pins? Also, can you post a photo of the power supply you were using.
- JWas
- Posts: 4
- Joined: Sun Jul 15, 2018 1:42 pm
Re: Rasp 3 B+ No Boot
The power supply is good - ripped from a computer. The 5 volt (pin 2) with ground (pin 39) gets 5.2, however, the 3V (pin 1) with ground (pin 39) only gets 1.5 V. See pic. Thanks
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- adafruit_support_carter
- Posts: 29469
- Joined: Tue Nov 29, 2016 2:45 pm
Re: Rasp 3 B+ No Boot
Backpowering the Pi through the GPIO header like this is risky. You are bypassing the input protection and power regulation that occurs when you power through the micro USB. So it's quite easy to damage the SOC. Those PC power supplies can be noisy.
Try powering with a USB power adapter through the micro USB port and measure the voltages again. But I'm thinking there is a good chance you've damaged the Pi with this power scheme.
Try powering with a USB power adapter through the micro USB port and measure the voltages again. But I'm thinking there is a good chance you've damaged the Pi with this power scheme.
- JWas
- Posts: 4
- Joined: Sun Jul 15, 2018 1:42 pm
Re: Rasp 3 B+ No Boot
I have the same results on the same pins. About 1.5v on the 3v3 pin and 5.2 on the 5. It's funny that you say the PS can be noisy. I've always had the understanding that these power supplies are very clean. I would point out the the results have been the same all along and the first time I connected this was through the micro USB - solid red light with no activity. I used the computer power supply because my thought was that perhaps the USB cable was lower quality. Thanks!
Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/