Perhaps the new LCD is DOA? What about fitting the old one back again to see if the camera behaves differently?

FWIW, this forum discusses replacing the LCD and there's photos available to registered users.

I also found this page with a fairly detailed step-by-step guide. Perhaps mentally going through the procedure again using this guide might help you come up with something previously overlooked?

Oh, and this is the (entire) FAQ from the aforementioned URL:

Quote:
1. My screen just shows white or gray. (E.g. white screen, white display). What did I do wrong?
A. The ribbon cable that connects the LCD to the circuit board was not inserted deeply enough. The end of the ribbon cable has a narrow portion, then a very small much wider portion with two holes at either end, then it narrows again. The very tip should be inserted into the "socket" deeply enough that the wider portion is pressed right up against the "socket." Physically, it cannot be inserted more deeply.
It may help you to use two wooden or plastic toothpicks, one in each of the small holes at the end of the cable, to push the cable into the socket.