Sir FICO
Posts: 31
Joined: Sat Nov 07, 2015 11:34 pm

Undervoltage detected on old Pi

Wed Oct 17, 2018 11:03 pm

Hello,
I have a Raspberry Pi 2 Model B Rev 1.1 that was running ok from a 5v 2A power supply. It was running jessie.

I saw there is a recent new version of stretch 2018-10-09 so thought it was about time I downloaded it and installed it. Rpi boots and runs OK but now it has and undervoltage warning and a lightning symbol when powering up. The Pi still seems to work OK.

Just in case it was the power supply going duff I swapped it for another 5v 2A supply, but the Pi still gives the undervoltage message on boot up. Only a keyboard, mouse and screen are attached to the Pi 2B and I thought only a 1.8 amp was ok for this model.

Is this an error in the latest stretch version ?? The old jessie on the SD has now been overwritten so I cant check the Pi with the old but this did not happen before.

Sir FICO
Posts: 31
Joined: Sat Nov 07, 2015 11:34 pm

Re: Undervoltage detected on old Pi

Wed Oct 17, 2018 11:48 pm

I suppose I should have tested with a multimeter before my posting - GPIO 5v to Ground pins shows 4.48 volts. I guess this is an undervoltage and stretch is correctly reporting it. Perhaps the Pi is failing. I will have to get a new one (and a new 2.5A power supply.

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Imperf3kt
Posts: 2978
Joined: Tue Jun 20, 2017 12:16 am
Location: Australia

Re: Undervoltage detected on old Pi

Thu Oct 18, 2018 1:06 am

More than likely its the cable you use between your PSU and the Pi. Low quality cables are a common cause of Pi power issues.
Your average USB cable is designed to transfer data and charge a mobile phone, not power a full computer + accessories.
55:55:44:44:4C
52:4C:52:42:41

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bensimmo
Posts: 4187
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Undervoltage detected on old Pi

Thu Oct 18, 2018 7:37 am

Check the uUSB connector, remove dirt and check the connections.
I've found loss there before, cable all fine just the connector.

fruitoftheloom
Posts: 21079
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Undervoltage detected on old Pi

Thu Oct 18, 2018 7:42 am

Retired disgracefully.....
This at present is my daily "computer" https://www.asus.com/us/Chrome-Devices/Chromebit-CS10/

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