Build Your Own Clone Message Board

I just assembled digital delay pedal (bezel free obsolete version,) that I bought from the dutch distributor Dr. Tube.
However the result is that there is no sound except via the by-pass but the LED lights up in the delay mode.
I checked the wiring and the soldered parts on the circuit board.
I noticed that I have soldered the TL072 in the reversed position (the dot on right side on bottom) on the circuit board.
So at a 180 degrees turned position as it is shown on your moderators picture ( the dot left top side )
Could this be the problem?
Please advise,
Best regards,
Arjen

P.S. Please note that I have also installed a 50K pot in order to extend the delay time. But I assume this is acceptable.
Also please advise SW2 purpose on switchboard. Why is it not used?

Powering a backward installed op-amp will fry it. Plug in another and as long as there are no other problems with the build you should be good to go.

The 50K will get you longer delay times but at the cost of distorted repeats at longer delay settings. If you don't have a problem with that you'll be fine. You could always modify the pedal to do both long and short delays by adding a switch and a resistor.

If SW2 isn't used in the build instructions don't worry about it. It's been too long ago and I don't recall why it's there. Maybe one of the others will chime in on that.

Thanks for your quick response.
I will replace the TL072.

Please help, for clarity I'll try to keep it short as follows:
1. I have replaced the op-amp, checked/tested most of the contacts and re-soldered all contacts (see picture below) but still no sound in the delay mode. (by-pass is working)
2.Q.: Pic of the top side of my PCB.
A. :
3.Q: Pic of the underside of my PCB.
A:
4.Q: Pic that clearly shows your footswitch/jack wiring and the wires going to the PCB
A:
5.Q: A pic that clearly shows your wiring going from the PCB to the pots and any other
switches(only if your kit has non-PC mounted pots and switches)
A: (see above)
6.Q: Is bypass working?
A: Yes the by pass is working.
7.Q: Does the LED come on?
A: Yes the LED lights up.
8.Q: If you answer yes to 6 and 7, what does the pedal do when it is "on"?:
A: Nothing. if the battery is connected and ticking with it on a table, I can hear ticking in the amplifier speaker.
9.Q: Battery or adapter.(if battery, is it good? If adapter, what type?).
A: Battery is 9V(not new 8,5V). Adapter is: Input 230V ~50Hz 8W. Output: 9.6V- 300mA, center pol. is minus

Please any ideas. Thanks, Arjen