I recently purchased a Raspberry Pi 3 Model B which I am beginning to think is damaged or defective.
I originally installed Ubuntu Mate to a 4gb Sandisk microsd card and ran the Pi that way for about 1 week. The pi constantly encountered a kernel panic and shut down, so I decided to switch to raspbian. But, no matter what I try, Rasbian Jessie Lite nor NOOBS will boot.
I have tried using win32diskimager, and Etcher to flash the Jessie lite images and have tried the following images on my SD card:
In each case, I get one green LED at boot, the red led, and one large rainbow square image (not the under-voltage square).
I have tried using GUIFormatter (linked somewhere in a forum) and the SDFormatter linked by the foundation to completely reformat the disk (including resizing the partitions and doing an overwrite format) and have tried Noobs 1.8,1.9, and 2.0 (the lite versions where possible as my SD card is small). In each case I get one green flash and the solid red light.
I am currently using a 5v 2.5a power supply purchased in a starter kit and have no reason to assume it is causing a voltage issue. I have swapped out the usb cable and the power supply (albeit for a lower amperage unit temporarily). I currently don't have access to a second microsd card, but I don't suspect this is the problem because each time I install Ubuntu Mate, the card works! I am not sure what other steps I can try.... which leads me to my post.
I am trying to determine if this Pi-3b is actually damaged before buying a new card or attempting a return. I purchased it a few months ago and just now had time to begin using it.