Stetsom 5keq

[luigidedom]

Have a stetsom 5keq with 4 opamps removed amp powers on and no other faults.
Would anyone be able to help with what opamps go where. I have an idea that there are 3 072 and 1 lm393
Board location U1 U3 U4 and U19

 

[cwillietc]

u4 is a 393 which send the square waves to u8
u1, u3 and u19 are 072