I got it all set up on my breadboard and it is working!!! Great!

Now that it is working I have two questions:

1. once the power is on and I wait a little bit before flipping the switch connected to U3, the green LED's come on immediatly, without any delay from the timer. When I flip the switch right after turning on the power the timer does its work.
How can I change that so that the timer does it's work no matter how long the power is on?

2. For the circuit to work I have to turn off the power after every duel. Is there a way to reset the whole thing without having to turn of the power?

I'm going to see if I can come up with an answer myself to both questions tomorrow. It's getting late here in The Netherlands and I need to go to sleep. I can't seem think 1's and 0's anymore.

Thanks again

 

Congratulations--almost. Be sure R16 is inplace, there should be +12V on both pin2s of U4 & U5; if OK try adding a diode in parallel with R16, cathode to + supply. What is the power supply?
To reset with power on, disconnect U6-4 from + supply, & add 10k from pin 4 to + supply, add a NO pushbutton SW from pin 4 to ground.

 

I'm still working on the Duelling Station but the last couple of weeks I've been busy working and making estimates so I can keep working.

I got problem 1 fixed, the timer will only start working once i push the button.

Problem 2 still exists.

There is also a strange phenomenon happening. Once the LED's have turned green and I 'pop' the balloon (with the switch), the blue LED won't come on unless I touch the wire running from the switch to U10 or U11.

For now I'm using a digital power supply.

I'll be busy for another week or so. Hope to have more time then so I can start working on the Circuit again

 

#2 U6 is normally at reset at end of matck, so all that is needed to restart is to momentarily short C3 to ground and Red's will come on. No need to change U6-4.
The wire from the SW-?? I presume is tied to +V, and used to register a hit on Y or Z by a momentary touch to U10-5 or U11-7.

 

Problem 2 still exists.

There is also a strange phenomenon happening. Once the LED's have turned green and I 'pop' the balloon (with the switch), the blue LED won't come on unless I touch the wire running from the switch to U10 or U11.

Not all breadboards are of the greatest quality so the spring tension in the breadboard holes may lost - especially if you have put a large diameter component lead into the hole in the past. Try moving the switches to another part of the board (e.g. up 10 holes) and try again. Same for the ICs that those wires connect to. The last option is that your yellow wire was used so often that it is broken inside and shorted internally. Just keep looking. It is not magic, there is an explanation and troubleshooting is the only way.

If you want to get more professional than trial-and-error, you can disconnect power and use your ohm meter and measure what actually shorts out or connects as you touch the wires.

 

There might be a question on how baloon SW's are connected, from grest picture, looks like R118 & R19 go from gnd. to SW & other SW contect to p-5 & 7. Added thumbnail to clarify.
What was solution for # 1 problem?