The DP isn't connected to the 7447 so it won't light up on LT low. The other 7 segments should light though. If the DP does light, then something is wired wrong to the display.
With LT and the two blanking pins set high, and the 4 inputs low, you should see a "0". Set input Q0 (1) high, you should see a "1". Set Q1(2) high and Q0 low you should see a "2". What do you actually see?
You could have a bad segment in your display or a bad 7447, or more likely, something isn't wired right. If you mix up the outputs and connect them to the wrong segments, you'll get gibberish. Also, if you set the inputs to a pattern that doesn't correspond to 0-9 (e.g. hex A through F, or 1010-1111) you'll get gibberish patterns as I don't think the 7447 blanks on invalid inputs.