Just want to share a bit my experience (I myself checked practically all those recommendations on my box) for the last c03ref by Stane. I have an advantage or reading in Russian and Spanish in addition to English and Ukrainian, so I found some useful info on foreign forums. My hardware appeared to be an Ider A10 box which is not a Vission model and it is important. The TV I am using is a very old one and my landlord will never provide a better one. It does not have an HDMI and this is also important.
In most of cases when the Dummies like me are changing their firmware with proper general type (c03ref for example), but from different model and at the end of the day they are finding themselves with a black screen - they are panicking without any strong reason for it. Most probably even the system is operational. Or maybe the system is not loading, but the system loader is still alive.
How to check if the system is alive - just insert a USB stick with a logical partition with FAT32 format and upgrade files and restart your Android (as you definitely did 1000+ times before). Go drink some beer, relax and then after 10-15 minutes switch it off and check your stick on your PC. If it has a ".Lost Files" directory - you are OK with the system. It is loading and is working, but you need to tune your video output. In the similar way you check if it is a Vission - compatible. Push in an SD card together with the stick and if you will see the folder on USB stick and no folders .Lost Files, DCIM and one more on your SD card - your system is not a Vission and you will have to survive without an SD
If there are no any folders even on USB - you are no longer a Dummy. You are a Bachelor now, because you managed to kill the system, but you still have a chance with the Loader.
1. In most of cases the Upgrade process from the Loader is going under HDMI
ONLY. So do not be scared if you see the black screen using AV output.
2. Another reason for black screen in AV mode might be caused by the resolution changed to a higher one than you may afford, or to an other type than is supported by your TV.
How to fix - find somebody with the HDMI, visit him with a box of beer, connect both HDMI and AV, install the firmware twice from the Upgrade of a system (this is with normal start), or from an Upgrade of the box (this is with those Reset, or Upgrade buttons) and then switch to AV and choose the lowest of possible resolutions and disconnect the HDMI. Then go to your home and pray that the type is correct. If it will not work - go back with a new box of beer, connect and change the type of TV for the same lowest possible resolution. Then you will definitely see the Setup on your TV and Stane`s firmware will no longer let you to spoil the picture. If you will choose a wrong one, or a higher resolution than is supported by your TV - it will just reset you back to a proper and lower one.
Do not forger to wipe the system and cash from the box Upgrade menu before the first installation of firmware.
If you will observe endless ANDROID sign during normal start - it means that only the Loader is left for you, so it is better to find any of versions of your original firmware, to reinstall it from the Loader and then to upgrade to Stane`s firmware. SD card in the Loader mode is operational even if you have a no-Vission model.
If you killed even your Loader - you are a Master and the next step for a Master will be to look for a dump of exactly your model and to say Hello to Linux. Look here:
Arm/Boot Loader/How to burn a uboot to board - Amlogic and be creative. My condolences in this case.
For no-Vission models - forget about your SD cards for now. Those models are using different way of addressing of USB and SD bus, so only a USB will be recognized for no-Vission models with the Vission firmware.
Well, a bit long, but hope that it will save a couple of boxes and a lot of gray cells of their owners. If not so - Mr. Admin is most welcome to delete this post as an off-top.
Good luck with the upgrades!
Was about to throw the stupid device out (f16ref) when I decided to give it one more go, one last firmware attempt. WiFi works perfect! Have been following this forum for a while and the help you have given people is unbelievable. Solid effort mate. 
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