Booting Raspi 3

[MalcolmB]

Friends

I am quietly going mad. I have a Raspberry Pi 3 and I simply cannot get it to boot. I have used a downloaded SD and bought two new NOOBS cards. To cut a long story short I end up in the same place every time: The screen fires up and the long listing scrolls through on the left. It then flips to the Rainbow screen and then to a little dialoge box under a picture of a raspberry. The dialogue box says "For recovery mode hold shift". If I do that it does to a screen headed NOOBS v1.8 - Built Feb 26 2016 and lists several operating systems to select including Raspbian, It says Installed next to Raspbian. I click on "Exit" in the header of the screen which when I hover over it has a banner that says "Exits and boots the installed operating system". When I click on that we go back to the long scrolled listing on the left of the screen and back through the rainbow screen to the "For recovery mode hold Shift" and we just repeat the whole game again.

What am I doing wrong? What do I have to do to get it right? PLEASE help.

[dgordon42]

First:

NOOBS v1.8 - Built Feb 26 2016

Currently, NOOBS is on version 1.9.0, dated 2016-03-18. Download it from here, and use it to overwrite one of the 'new' NOOBS cards you bought. There have been many reports on these forums of vendors selling out of date NOOBS cards, especially with the release of a new product.

Second:
Whats happening with the red (power) LED? Any sign of it flickering? This would indicate that the power supply is not up to the job of powering a Pi 3.

Finally:
Have a look through the boot problems sticky post. There's a lot in it, but it covers just about anything that can go wrong.

Hope this helps,
Dave.

[MalcolmB]

Thank you replying. I wiped a Micro SD using the SD site and then carefully downloaded 1.9 onto my computer and extracted it to the SD. I put that into the Raspi3 and powered it up. The outcome is identical. Insatalling the OS reported successful. The NOOBS window listing the operating systems available is headed v1.9 Built Mar 18 2016 so I have got the latest one. I click on "Exit"(Esc)
and the thing goes back to scrolling all the Start-up listing, goes to the rainbow screen and then to the Recoverymode with Hold shift. If I hold shift I get the list of OS again and everything repeats all over again.

Something is wrong - surely someone at Pi headquarters must know? PLEASE stop me wasting time and get my Raspi working for me.

[rpdom]

What happens if you don't press Shift?

[dgordon42]

I am still wondering what you are using for a power supply.
Have you, at any time, noticed a small multi coloured square 'icon' near the top right of your screen?
Have you, at any time, seen any flickering on the red power LED?
The Pi 3 needs a bit more power than the previous models to work correctly. A poor power supply can cause the Pi to reboot when the processor gets busy, and so it can look like it's going around in circles.

Dave.

[MalcolmB]

Dave,

You are giving me hope. Thank you.

Yes, I have the multi-coloured (miniature rainbow square) in the top right. What does it mean?

The PSU I use is the one supplied by Maplins in my Raspberry 2 kit which worked fine. It says it output is 5v at 2.1 amps. Any good? Do I need a bigger one - how big?

Malcolm

[MalcolmB]

Dave and rprandom

Sorry, I should also have said that the red LED goes on and off. It might could have a regular pattern rather than just flashing.

If I don't press the shift key they whole thing just goes back to the start of booting anyway.

Thank guys

[dgordon42]

Yes, I have the multi-coloured (miniature rainbow square) in the top right. What does it mean?

Sorry, I should also have said that the red LED goes on and off. It might could have a regular pattern rather than just flashing.

You Pi 3 is not getting enough power to run correctly.

It looks like your Pi is rebooting dut to lack of power, as I wrote in a previous post
The power supply of choice for a Pi 3 is this one, also available in white.

You might find that your Maplin Kit supplied power supply lead is causing you problems. If you have another USB to microUSB lead, say from a smart phone charger, try it.

You should also be aware that, as your Pi 3 seems to be rebooting due to low voltage, it may corrupt your SD card, so you may have to reflash NOOBS onto one of your cards.

Dave.

[MalcolmB]

Dave
I have been out and bought a 2.4 amp PSU and that made no difference.

What does the coloured symbol in the top right mean?

I will reload the SD card.

Thank you.

[kusti8]

Dave
I have been out and bought a 2.4 amp PSU and that made no difference.

What does the coloured symbol in the top right mean?

I will reload the SD card.

Thank you.

The colored symbol means it's not getting enough power. You bought a new PSU but did you change the lead? That could be causing your problems.

[dgordon42]

What does the coloured symbol in the top right mean?

The small rainbow square on the top right of the display indicates that the power supply voltage has dropped below the minimum (4.65V I think) for proper operation. The absence of, or flickering of, the red LED also indicates a low voltage power supply.

Quite often, these problems are caused by the use of very thin copper in the lead running between the power supply and the Pi. The best power supplies have built in power leads, like the models I linked to previously.
If you have any other leads, try them. In general, the thicker and shorter the lead, the better.
There are lots of cheep phone chargers out there which do not always work as advertised.

my Raspberry 2 kit

I did not know you had another Pi. An up to date SD card which boots a Pi 2 will boot a Pi 3. This will allow you to test and verify the status of your SD cards!

Hope this helps,
Dave.

[MalcolmB]

Dave,

Congratulations, I am impressed. You have got it.

I have wiped and reloaded my SD card again in case I have messed it up.

But, critically, I have also fitted a different USB cable (from my wife's phone, my iPhone 5 has the wrong kind of connector). This is what has fixed it. I had no expectation at all that this could possibly be the problem, thank you for keeping on saying it, I was not listening.

It has fully booted and I am in business.

I am stunned that changing the cable is the answer. I will check it out tomorrow.

I cannot express my delight and gratitude, please feel very pleased with yourself indeed, you deserve the satisfaction. Your persistence is an example to us all.

Thank you very much.

[stderr]

The best power supplies have built in power leads,

I think it is more fair to say that power supplies with built in leads will be more likely to consider the leads and the power supply as a unit and therefore the leads will be designed for the power capabilities of the power supply. I don't think there is any reason why a high quality power supply couldn't use removable USB cables or any reason why someone couldn't buy high quality power capable USB cables for something like that. I think that that is often not done leading to the problems here. There are advantages to removable leads including being able to buy them at the proper length for an application, that isn't likely going to be an option when they are attached to the power supply.

[MalcolmB]

You make a good point. When I went out to buy my new PSU I carefully selected one with removeable leads.

I had a choice.

Of course I made the wrong choice!

All this is completely news to me.

But, it s all about learning, which is supposed to be good for us.

Thank you again.

[ABK]

the joys of the internet people helping people. i luv it

[dgordon42]

MalcolmB,
Glad you got sorted

any reason why someone couldn't buy high quality power capable USB cables

This is the problem. It requires the manufacture of the cable to declare the material and thickness of the power carrying conductor in the lead, something that I have not seen much of, in order to determine quality. The original USB 2.0 spec only specified 0.5A per device. A Pi 3 can need up to 2.5A, 5 times as much. We are relying on non-standard smart phone charging cables, and so the whole thing is a bit hit and miss. A new smart phone, with a big battery, may come with a suitable high current lead, but an older phone may not.
If you buy a power supply with an attached lead, the power supply should meet it's specs at the Pi end of the lead, not the power supply end of the lead, as is the case with a detachable lead power supply.
If the OP had used an industrial standard 5V, 10A power supply, his Pi would not have worked due to the poor power lead. To be fair, the OP's 'poor' power lead would likely work with a 0.5A USB device. It may even charge his wife's smart phone!

Dave.