First step in debugging any circuit is reporting relevant DC voltages such as inputs and outputs ( or all pin#)
Set pot to middle. Learn to use Reference Designations like U1, U2 and pin numbers. U1-1
1in- =
1in+ =
1out =
2in- =
2in+ =
2out=
Vb=
Ve=
Vc=
Then realize OpAmp when (-) is not = (+) , the output is not linear or working , meaning will saturate to +/- rail. Positive feedback does this. (hysteresis)
Then use logic and input voltage, If inputs not the same then (+) > (-) then output must be high.
Beware input linear range is not full scale on 741 and 5V single supply reduces range alot more than rail to rail type Op Amps.
Then realize where schematic is coming from and may not be optimal or values are not optimal such as +ve feedback ratio.
Then make a better design. Substitute for the obsolete parts below. Since this was made for bipolar supplies. change the ground symbol to V+/2 using an R voltage divider to V+/gnd such as 10K/10K with a cap across it.