Often after replacing the LCD on a Unison CE processor, there may be backlight but no characters. It's most likely the contrast is now too low for the (at the time of this publication) current 7080B5067 part number. Because it is near impossible to adjust the contrast on the dimming engine while the whole thing is assembled, you'll want to get the contrast right on the first try after disassembly.
Using the picture below, adjust the Contrast Adjust P4 pot on the dimming engine so the resistance between pins 2 and 4 of the LCD connector J4 read approximately 1k ohms. Put everything back together, and the LCD output should now be visible. (If not, and this was being replaced due to damage to the processor, U24 will likely have to be replaced and given new dimming code by ETC.)