Bought one of these from ebay. Not had any luck getting it to display anything so far. I've tried three different versions of driver libraries. The display flickers when the test code is running but nothing is displayed and the screen stays pretty much white.
The touch panel works and serial output is occurring.
Chip code is c0c0 and this appears to be identical to the board sold by womart (appearances can be deceptive though).
I did manage to short the bottom of the board to the usb connector when first connecting. I read somewhere that suggests that this could cause damage however, the contact points there are 5V and Ground. My 5V (and 3.3V) are still good.
Next step is to verify that my arduino is working correctly. This is a new unit so relatively untested. I am not expecting to find anything here but we shall see.
After that, hopefully it's find some data on the display chips and write some simple test code to see if I can get anything on the display at all.
I'll probably also order another display in any case. They're cheap enough.
Not really expecting a whole lot of troubleshooting help on this but just putting this here in case what I find can help others.