Pi3 undervoltage issue

[chaozz]

I got a Raspberry Pi 3 from TinyDeals to review on my Youtube channel. However, when I run Raspbarian or RetroPie the device does boot up, but I get a permanent yellow lightning bolt in the top right corner ("undervoltage"). This error occurs when not connecting any USB device, but when I do connect one it doesn't work (optical mouse won't turn on for example).

I have tried different SD cards (that all work with my Pi0), different phone chargers and ended up buying the official Raspberry power supply (I have two, brand new). All to no avail.

A short summary:
* the unit boots into raspbian
* the hdmi output works
* using the official power supply (that also powers my zero)
* using an sd card and image that works in a different Pi2
* lightning bolt appears, even with no USB devices plugged in
* plugged in USB devices don't work
* the green activity LED doesn't turn on (LED is not broken, that was tested)

Can anybody shed some light on this?

[jahboater]

I have tried different SD cards (that all work with my Pi0), different phone chargers and ended up buying the official Raspberry power supply (I have two, brand new). All to no avail.

Is it the official power supply for the Pi3? It is uprated compared to the Pi2 one (5.1V 2.5A 18AWG cable).
Almost any PSU will cope with a Pi Zero, it doesn't draw much!

[peterlite]

The Zero will work with about 0.5 amps. The Pi 2 requires 2 amps to run the extra core and Ethernet. The Pi 3 requires a 2.5 amp supply to run the extra cores plus Wifi and Bluetooth. 2.5 amps gives you the power to run the Pi 3 with keyboards, USB 2 storage, everything smaller than a 2.5 inch disk.

Some of the official raspberry Pi power supplies are the 2 amp supplies for the Pi 2, not the Pi 3. They work with nothing plugged in then fail when the USB ports on the Pi 3 are loaded.

The Pi 3 has the smallest acceptable voltage range of anything I use. The slightest startup voltage drop will stop the Pi 3. A power supply with wires too long or too thin. The wrong devices plugged in. The wrong phase of the moon.

[chaozz]

The official PSU I am using is 5.1v / 2.5A.
It's this one:
https://www.kiwi-electronics.nl/raspber ... -5a--eu-uk

[FTrevorGowen]

...
I have tried different SD cards (that all work with my Pi0), different phone chargers and ended up buying the official Raspberry power supply (I have two, brand new). All to no avail.
...

Just to clarify - how up to date were those cards? (It may be worth posting the output of uname -a)
What happens if you try a fully up to date version on a new uSDHC card (after the updates etc. given in the blog:
https://www.raspberrypi.org/blog/introducing-pixel/ ).

The official PSU I am using is 5.1v / 2.5A.
It's this one:
https://www.kiwi-electronics.nl/raspber ... -5a--eu-uk

That should be fine. My P3B works fine with the (P2B) 2A variant, but I'm not using anything with it that requires significant USB current.
Trev.

[chaozz]

Just to clarify - how up to date were those cards? (It may be worth posting the output of uname -a)
What happens if you try a fully up to date version on a new uSDHC card (after the updates etc. given in the blog:
https://www.raspberrypi.org/blog/introducing-pixel/ ).

I've tried several. Including the one that came with my Pi zero essentials bundle. They're fine. And I can't run any commands, because as I stated, none of the connected USB devices work. That includes keyboards, sadly

[FTrevorGowen]

Just to clarify - how up to date were those cards? (It may be worth posting the output of uname -a)
What happens if you try a fully up to date version on a new uSDHC card (after the updates etc. given in the blog:
https://www.raspberrypi.org/blog/introducing-pixel/ ).

I've tried several. Including the one that came with my Pi zero essentials bundle. They're fine. And I can't run any commands, because as I stated, none of the connected USB devices work. That includes keyboards, sadly

Not on the P3B, but you should be able to on the Pi Zero??? Where (and when) did you get the "Pi zero essentials bundle" - did that include a "pre-loaded" uSDHC card? (If so, especially if it was for the first version of the P0, then it may contain a version of Raspbian that is too old).
Trev.

[chaozz]

I formatted the SD already and installed the latest Raspbian, and latest Retro Pi later. To no avail.

[FTrevorGowen]

I formatted the SD already and installed the latest Raspbian, and latest Retro Pi later. To no avail.

Ok. Either something's (partially) tripped the P3B's polyfuse (give it 48hrs and try again**) or you have that "rare thing" a faulty Pi.
Trev.
** Whilst you're waiting check the PSU's off-load voltage (>5.1V?), just in case that's faulty. W.r.t. retrying the P3B, do it first with a minimal (no USB stuff) system first and measure the voltage between the 5V & 0V pins - it should be <=4.65 V if the "lightning bolt" is being displayed correctly. Check also if the red PoWeR led is flashing.