I'm having the same problem. When I boot my Lumia 520, I get the Nokia screen then the BSOD. i.e. a sad face emoticon in landscape mode.
I've tried the following:
-removed and replaced the battery, SIM card and 64 GB SD Card
-tried a reset
Still getting the BSOD
Can I confirm that I'm doing the reset correctly?
1. Phone off
2. Press Power button (just press or press & hold?)
3. Press and hold Volume down (should get exclamation mark)
4. Press Volume up, volume down, power, volume down.
At step 2 & 3, I've tried both press & hold both power and volume down as well as press and release power, then press and hold volume down.
No matter what I do, I can't get anything other than the BSOD.
Am I doing something wrong?
Resolution.....
I continued to fiddle with this issue. In case anyone has the same problem, here's my resolution.
The phone wouldn't reset and the Nokia Software Recovery tool didn't work either. It seemed to reinstall the software but the phone wouldn't reboot at the end of the process.
As a last resort, I removed the 64GB and left it out as I attempted another phone restore. It worked. I suspect that if I had simply removed the SD card, the phone would probably have worked correctly without the restore. (I had previously moved all possible apps to the SD card. During the boot process, the phone probably looked for these apps, couldn't find them then refused to boot.)
I subsequently attempted to read and reformat the SD card in my computer. The computer failed to recognize that it was inserted. Therefore, I'm pretty sure that it is defective.
Further info....
Both my wife and I have Lumia 520s. The problem above occurred on wife's phone. However, my phone just encountered the same problem. I removed the SD card and it works perfectly (except for all the apps and data on the SD card). I didn't reset the phone.
This is very suspect. I find it an odd coincidence that 2 SD cards would fail in exactly the same way within a couple days of each other. However, they were exactly the same model and size of SD card. Nonetheless, they had been working fine for about a year. About a month ago, both phones were updated to Win Phone 8.1. I'm wondering if the OS had been silently updated in the last few days. The phones both show Windows Phone 8.1 version 8.10.12393.890 (I don't think that this is 8.1 update)
If anyone has any thoughts I'd love to hear them.
More thoughts....
As I'm thinking about this problem, another thought occurs. There is usually some significant event that precipitates a computer/smartphone problem. The last (and recent) significant event to occur on both of these phones was the installation of Lumia Storage Check Beta which allows me to move the Maps apps to the SD card. I did this and subsequently download several maps to the SD card. There wouldn't have been enough room on the phones main memory for these maps. My apps are also set to automatically update. My wife's phone was the first to see the BSOD problem and her phone had been turned on much more than mine.
In further research on Lumia Storage Check Beta, I found a site which reports that the Beta trial has been concluded and an app called Storage Sense is included with Win Phone 8.1. Further, Lumia Storage Check Beta is not compatible with Win Phone 8.1. I didn't previously know this and since Storage Sense wouldn't allow me to move Maps to the SD card I installed Lumia Storage Check Beta anyway. It seemed to work initially but I suspect that the incompatibility caused my problem during a Maps update.
Again, I'd be interested if anyone else has seen the same sequence of events.