I have the same model with the same problem. I tried to adjuest the brightness down a bit and it went completely dark. Now with a full restart, I see the cute little start-up routine (so the screen itself is still fine) but when the boot is completed, the screen goes completely dark. What's not possible is fixing this through any menu (can't see them) or a combination of buttons (systematically tried every combination).
On another forum, someone "helped" by pointing out the inferiority of the chipset in this particular device. That is perhaps interesting, but hardly useful. I'd really like to know if there is a solution, since I was just getting to find the tablet a bit useful - and fun.
Thanks in advance.