2 RPI3 with 2 SD both not booting

[ajm1403]

Update:

<paranormal theme music>

Same Raspberry Pi 3, same SD cards, same power supplies.

The machine now boots and runs. Nothing changed. Except for additional insertion/remove of SD cards and possibly some pressure on the SD card socket.

All of the (untouched, i.e. not re-written) cards that failed yesterday evening are working this evening. .

I hope we're not back to needing spring clothes pins as a required accessory.

Background: I am a 30+ year software engineer who understands how to troubleshoot, track configuration changes, change one variable at a time, etc.

[pingpong2012]

I had an issue where I'm 99% sure it was because I was using an old version of Jessie. I downloaded the new one, accidentally burned the old iso (didn't unzip) and spend a good half hour or so going through everything.

Im using my RPI 2 Power Supply Cable and NOOBs Works and in the process of installing Raspbian but Ubuntu Mate Gets that Small Rainbow Square.

It's a power supply issue. Period. If you have too many peripherals plugged in, it can happen. I would normally run the Pi off of a hub (using the hub itself to power the pi). Didn't have any issues with the Pi 2. I don't think I did that with the Pi 3, but the Pi 3 did give me rainbow square with two different supplies, if I had a wifi dongle plugged in. Both of the USB powers I tried advertised at least 2A. With only a small adapter for a wireless mouse/keyboard, I haven't seen the thing re-appear. Afterwards I have started using the official pi 2.5A adapter, and haven't seen it.

Even though I had the rainbow square while running the Pi 3, everything worked fine when I was expanding the system, updating, etc.

[MangoCats]

I am having the same experience with a new Pi3, I have two working Pi2s on my desk here, trying to start with a fresh Jessie image on the Pi3, but I just hang at the Rainbow screen, both on 16 and 32GB class 10 SD cards. 2.5A PS from CanaKit, swapping PS and SD cards with the working Pi2s the problem sticks with the Pi3 - though the 64GB card that works on the 2 gives a different (big and little Rainbow squares) image than the new Jessie.

I notice that my Pi2s have a spring-kick back on their SD card slots, while the Pi3 is just a friction fit... I haven't had the "suddenly working for no reason" moment yet...

[pwillard]

Same issue. My Pi3 is basically a piece of rubbish, right out of the wrapping.

[RaTTuS]

Same issue. My Pi3 is basically a piece of rubbish, right out of the wrapping.

ok send it to me and I'll put it to good use
or read this
viewtopic.php?f=28&t=58151