Just for the record, I've received my Omega 2+ and it's working fine. With the help of the community, I've got the LEDE cross compiler working in a hyper-v machine and a hello world C program running on the Omega. Nice! Now to start something a bit more adventurous. 
@Lazar-Demin OK, so it's been almost 2 months now and despite my ticket being closed 3 times saying it's been resolved, and a promise of a replacement Omega 2+ which would be delivered within 2 weeks from 14th March, it hasn't happened. So I've raised a new ticket (#8161) because I can't re-open the old one. To say the least, I'm very disappointed to have paid for this last year and I'm still waiting nearly 6 months later. Not an easy introduction to Kickstarter for me!
@Johan-Charpentier Did you get a replacement?
At last, a result. Onion will be sending a replacement in the next shipping batch. Better late than never.
No update on my ticket as yet. It has been closed again with no indication of what course of action I should take. I've been waiting almost 3 months now. I'll re-open the ticket and ask for a resolution.
@Hummed Another week on and still no update on my ticket. And to rub it in I get an email broadcasted from Onion today to say creating a ticket is the best way to resolve an issue. Maybe it's because of the Chinese new year celebrations. Still it's encouraging that I'm not the only one with this issue.
In the meantime, I'm having great fun with Particle Photons that just work.
@Lazar-Demin Thanks Lazar. I can see that one of your hardware designers is working on my ticket now.
I'm the OP and have followed the RMA procedure to the letter but have had no response from Onion other than to close my support ticket saying it will be resolved by the community. I got the ticket reopened on 28th Dec and it's still open with no response so far. Please Onion, a month has passed and I've had no advice from you or the community how I get my device running (I don't have solder reflow capabilities, besides it will invalidate any warranty with you). There's at least 3 of us now that have the same problem @Johan-Charpentier @Wai-Weng-Kong . Help please...
@Larry-Pinney Can't just return it without a returns number.
I stated on my support ticket that it could be the wrong firmware but haven't had any response from Onion about the issue at all.
Note that my board says:
Board: Onion Omega2 APSoC DRAM: 64 kB
but yours says:
Board: Onion Omega2 APSoC DRAM: 128 MB
Yours is reporting the correct amount of DRAM but I've got as much as a 1980's 8-bit CPU 
.
Hi @Wai-Weng-Kong Unfortunately, no the problem has not been sorted. I logged a support ticket to get advice about how to resolve it but Onion just closed the ticket saying it would be resolved through the community site. Onion has reopened the ticket for me but has not provided any suggestion of how to get it working. So at the moment I have a faulty Omega 2+ that is sitting on my desk gathering dust. A nice welcome to my first kickstarter reward!
I'm pleased someone else has the same problem as me, in that it's not an isolated problem, but I'm sorry you're in the same boat as me 
. I hope this spurs Onion to suggest what to do even if it's a return.
@WereCatf Ah, well spotted. Just guessing but maybe one of the address lines isn't connected correctly, or a solder bridge between pins. It's all under the cover so can't see.
@fossette Good spot @fossette. An Omega 2 Plus should have 128MB of RAM memory. Wondering if this is on the board as 2x64MB chips and one of them isn't responding. Maybe the bootloader can't complete it's memory integrity check, on the assumption it does one.
Further update:
Thanks for the advice so far. Really looking forward to playing with this due to its tiny size.
@Luciano-S. I've added a couple more photos to show the pins on both sides of the Omega2+ board have been inserted correctly into the expansion board. There's also a photo showing the inside of the headers to show none of the pins have folded back underneath the board.
I'll try some other USB cables today and see if that makes any difference.
I've just received my Omega2+ with expansion board and followed the Get Started instructions to connect it to a Windows PC via a micro-USB lead, but quickly hit some problems.
The LEDs on the expansion board and on the Omega2+ don't light up at all when power is applied.
I can see the Omega2+ write this out to the serial console using Putty on my host PC (115200 8N1):
Board: Onion Omega2 APSoC DRAM: 64 kB
relocate_code Pointer at: 7ff70000
This photo shows the Omega2+ is connected via COM5 because it's connected via a powered USB hub. It connects via COM3 when connected directly to the host PC.
Linux does not start up and the AP is not visible using a WiFi analyzer.
I've tried with different USB leads connected direct to the host PC and via a powered USB hub (which incidentally powers a Particle Photon, Olimex JTAG programmer and Logic Analyzer just fine), but I always get the same result.
The Omega2+ is plugged into the expansion board correctly as shown below.
I've checked the 5V and 3.3V power lines on the header socket with a digital meter and they are present. The RF screen on the Omega2+ does get warm but I would expect that.
Can someone tell me why it's not booting up?
Edited 24/12/2016 - added a couple of more photos to show the both rows of pins inserted into the headers and one of underneath the Omega2+ to show that no pins have folded inside underneath the board.