Look at the image. I bought some CC 7 seg drivers for a student. And per a request I wired a CC 7 Seg circuit to show, I did the same with a 7447 with a CA and it works. The 48 did not work. Checked them all 20 pcs. Just one seg lights. All chips the same. Tried the LT pin and does not work. Tried all the combination of RB in out pins and still the same. I gave up. I swapped the 48 and CC to a 47 and CA and the circuit works. So I know the wiring is correct. I was wondering as why all the 20pcs are showing the same. Could be they are counterfeit ? Has any one came up with this issue or am I doing something wrong ? datasheets attached for your convenience.