"Aren't there extra RAM slots on the motherboard (requires cover remove"に関する回答It's often cheaper for manufacturers to only buy one type of RAM chip ie. 2 slot supporting, and simply only install one physical ram slot, so Windows might see "two available" however that is what the control chip is seeing not the physical available slots. My Lenovo T440 is the same way.
"How do I replace T83 TELSTRA DAVE 4G screen LCD"に関する回答I just uploaded a guide on how to replace the display assembly, hope it helps. Telstra Dave 4G ZTE T83 Display Assembly Replacement