I found this police siren schematic on the internet. At first it seems really strange to me that on the first ne555 pin 2 and 3 are not marked, but I build something similar in falstad, connected pin 2, 3, 6 on the first ne555 and it worked??? But when I build it in real life, it doesn't work, just squeal and two ne555 got really hot. Is there problem with this circuit, because it seems strange. I really tried to check all possible misconnections and all the details before I solder it. Thanks for help!
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