MacBook Pro (Mid 12, 13") not booting OS X Yosemite - "No sign" on boot My MacBook Pro Mid 2012, 13" currently works with a HDD (on newest OSX). Now I connected a brand new (completely tested) SSD (Transcend SSD370S 256GB) to the HDD Strip inside the macbook.

I've made a bootable USB-Stick with the newest version of Yosemite with Terminal this way:

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Name-des-USB-Sticks/ --applicationpath /Applications/Install\ OS\ X\ Yosemite.app/ --nointeraction



Now a started the MacBook, hold down Option Key.
Booted from USB stick
Formatted SSD as Mac OS Journaled, 1 Part. GUID
Installed Mac OS X on Volume "SSD"


On finish of OS X Installation I clicked on "Restart" and the MacBook did a reboot, after the reboot it show the "international no" sign appeared.

After some seconds the MacBook started the Installation from the USB stick and shows up the the "Install OSX" again...

I also used the Disk Utility to repair and verify options.

Edit #1:
While writing this question, I tried it again and after a short period of the "no-sign" (about 5sec) the "OSX-Installation-Finish" screen appeared, but I don't think this is "good" at all.

Edit #2:
After setting my system language I needed to reboot again and now It is trapped again in the "no-sign" mode
Fixed it. It's so curious I didn't thought this was even possible. When I removed the connector of my optical drive, the macbook starts. When I connect it, it shows me the "no sign"

1Mio. Dollar Question: Why doesn't it boot with SSD but with HDD?

Edit:

The bug wasn't the SSD or the HDD, it was the the HDD flex cable. Firstly I connected my SSD with an OpticalDrive-to-2,5"-Drive-Adapter and it worked like a charm. So the only possible defect should be the flex cable. Bought one on ebay for 40 bucks and replaced it. Now the macbook works without any problems.

Edit #2:

Apple already claimed there is/was a fault with the HDD flex cable. But it's not public stated - so you had to ask apple. Found this news article – So I just called Apple, because I already replaced it on my own. Apple said that they can't replace it "again" but they can refund my replacement. So 2 weeks later I got a full refund of be ebay invoice.