When attempting to boot up my first RPi3 Bv1.2 I purchased from Newark (an Element14 IoT Learner Kit) it would NOT boot. I have the SD card installed, HDMI cable and monitor and then plugged in the provided power. I tried this multiple times. I then opened the second box, i.e. new everything.... It did not boot up either! The red LED was on in both cases but the green ACT never came on and there was no video.
In reading the help files scattered throughout the internet and it all came back to people stating power issues or SD card issues, generally. So, with the red LED on I started pushing around the SD card by putting it in 100%, ~95% of the way, ~90%, 85%, etc. trying the second system the same way. Then I bumped the SD card sideways on my last attempt while plugging the power and bingo, green light started flashing and video appeared..... Lesson is as most say, a SD card issues and if you wiggle it around hopefully find the sweet spot.
Hopefully, this post helps others and hopefully them Pi baker's will work on providing a better SD connector.... RS
