I have a batch of 9 Raspberry Pi's bought together within the last week. I created a custom image on one with whatever software I required installed.
I used dd in Linux to copy the custom .img file to SD cards for the remaining Pi's.
The problem is 3 of the Pi's are failing to boot up. The SD cards came with the Pi's from a reputable vendor. I have tested each SD card individually and they are all booting on various Pi's except the 3 in question.
I never tried to use the NOOBS installer supplied with the SD cards and the first time I booted these devices was with the custom image.
I have tried using various power supplies but this fails to resolve the issue either.
When I power up both red and green LED's come on solid. The green LED fails to flash at any point during the process.
sudo apt-get update && sudo apt-get upgradeand try rebooting again with newer Rpis. Hope it helps.