RED / GREEN LED on Pi 3 ?

[julyjim]

What exactly is RED LED , next to the micro USB plug, telling me?
I assumed it is a power indicator , but it goes off same time when yellow lightning icon {?} appears , generally in upper right corner of the monitor. My best guess it means power trouble, but the PC seems to be working just fine when that happens.
Hence my question - what exactly ( low level of what ? and how low ? ) is RED LED telling me?

Similar question about GREEN LED, it seems to be going off at random.

[davidcoton]

Red LED is power, if it goes off the input voltage from the PSU has dropped below 4.65V. Still enough to run the Pi, but USB peripherals (and possibly HDMI) could be in trouble.
Led off = lightening bolt on. You need a better PSU and/or microUSB cable (short and thick is good).

Green LED is SDCard access.

[julyjim]

Thanks, now I feel better.
On my first power up I run too many USB devices (wirless keyboard/mouse, external HD, digital photo camera, video camera) when I noted the red LED and the lightening!
I am offloading all to D-link hub next.

Did not really expect it would work with 1A power supply I dug out from my "box of junk".

I need to work on bluetooth to get the keyboard / mouse off the USB port, next.

[tweak42]

Thanks, now I feel better.
On my first power up I run too many USB devices (wirless keyboard/mouse, external HD, digital photo camera, video camera) when I noted the red LED and the lightening!
I am offloading all to D-link hub next.

Did not really expect it would work with 1A power supply I dug out from my "box of junk".

I need to work on bluetooth to get the keyboard / mouse off the USB port, next.

Keyboards and mice tend to use a minimum of power. But hard drives and cameras definitely can strain, and usb wifi dongles can jump pretty high when under load.

[rpdom]

Did not really expect it would work with 1A power supply I dug out from my "box of junk".

The recommended power supply for the Pi3 is 2.5A. The official ones are reasonably priced and work well.