hi elementofice,
sorry for delay, just got my MBP Retina back and it's got Yosemite on it!!! *backflips*
they swapped the MLB out and this has done the trick for me at least.
They pushed Yosemite onto my machine via the AppleStore Ethernet network when I collected my computer, the whole thing was installed within around 10 mins. Beautiful and another notch for good customer services inside Apple Stores! 🙂
I've currently restoring my docs onto it from my external HD, so not quite fully operational but I'm getting there.
A note on your rig. You have upgraded your disk and your RAM.
Although I didn't believe it at first, the Yosemite installer does seem to do a HW check on your rig during setup.
Hence Yosemite install may have issues, but Mavericks install will be ok to drop back down to, so all should not be lost.
In my case I started my machine holding the 'D' key down to get to Apple's Diagnostic Test, which highlighted my 4Mem error.
From what I have been able to read up, it seems to me that people who have upgraded their rigs with 3rd party memory (even reputable brands) were experiencing installer issues. When they put their factory supplied memory back in, Yosemite installed fine, after which they swapped their RAM out again for it to continue to work without problems. Check further up this thread for more info.
I have no idea why this is happening or what is going on here and this wasn't my problem as my memory was soldered onto my logic board and I had the original factory hardware in my machine.
All I'm saying is, if you have your original RAM parts lying around, it may be worth dropping those back in to try and get Yosemite installed.
I can't seen how a your upgraded SSD would hamper your installation, but I would check out and revert to original RAM for sure as this is a main component on the Apple MLB which it obviously does a check on during install.
getting Mavericks Installer:
It sounds like you've been on the same Yellowbrick road as I have with the Yosemite installation. You've managed by the sounds of things to do a backup or/and a disk image copy of your HD (this is what I did) using the DiskUtility App to get to the stage of wiping your SSD clean in prep for the install. This is good, this is what I did, so I didn't have to worry about my data at all.
In my case, I already had a Mavericks installer stub on a bootable USB key (from way back when).
Mavericks should be available as a download from within your AppStore (it was in my case, it was there as a download from when I upgraded to Mavericks), but as you probably wouldn't be able to get into that right now, you would have to login to your AppStore on another Mac somewhere and download the stub file again. I would suggest you download the most current installer stub from the App Store as I think Apple do release updates to these stubs, meaning you will get the latest Mavericks installer, this is what MacWorld suggest anyway.
(Remember that once it's downloaded, you shouldn't run the installer there and then - just cancel/quit out of it and the stub will remain hidden on the machine).
This is a handy guide as to how to create your bootable USB drive to load into the Mavericks installer. I didn't need any fancy 3rd party software to make the bootable USB drive, I just used Apple's DiskUtility app for this and this worked perfectly.
http://www.macworld.com/article/2056561/how-to-make-a-bootable-mavericks-install -drive.html
Afterwards, you should be able to boot up using the USB key, and re-install Mavericks. From my personal experience, Mavericks re-installed initially without harming any of my documents and files. However, you know what they say - have your backup up-to-date.
That should get you back to Mavericks at least.
As for Yosemite, if you drop back the original Apple factory RAM, and the Yosemite install still doesn't work, you will defy need to go to a Genius Bar and have a chat with them, letting them know you've been enjoying full round trip on this affair. They can hook your computer up to their network and run an additional HW diag on your system.
In the end, what did it for me was a logic board replacement.
I could still be running Mavericks today not having had any inkling about any hardware issue with my machine, but the Yosemite installer was particular about this and highlighted it.
Hope this helps.
