input in full adder and output in 7 segment

I have this project that we will use a full adder and output it in a 7 segment display..
I already set it up but it has some few errors.
I used a 4 BIT ADDER (74LS83) but kept the MSB at 0 (GND) because our input has to be 3 bits only and a BCD-to-7 segment decoder IC (74LS248)..
the problem now is that it doesn't output some numbers correctly..
like

-when I input 000+000 the display is not zero, all are lit except f.
-the B0 is not working, whether it be 1 or 0 the display doesn't change.
-when only A1 is 1 the display that is lit is a,b,d,e,f.

I've checked my connections many times and it is as the diagram says.. did i do something wrong or is the IC (74LS83) defective.. TIA

here's the diagram
i25.photobucket.com/albums/c93/Luke_XIII/diagram.jpg?t=1223059159

What is your C0 pin tied to? It should be tied to zero for active high. Also the output of the adder is not BCD so you will not get what you want as your diagram is shown.
Take a look at binary addition.
https://courses.cs.vt.edu/~cs1104/BuildingBlocks/arithmetic.010.html