reacher10:
5v and ground from one power supply (USB) going to the VCC and ground of the pro mini5v and ground from another power supply going to the back light on the TFT
5V and ground from another power supply going to the VCC of the TFT.
That is 3 different power supplies. 2 of them for the TFT.
Not sure what you mean by different power supplies: One source for the thee cases will be enough.
Oliver