Here's one... If I had a circuit that made use of a 555 timer chip, but it was not marked in any way that I could identify as the markings or a 555, how could I confirm that it was indeed a 555 timer chip? Still working on wireless remote for automatic door opener that doesn't. I believe I have confirmed proper function in the three transistors, but it looks like the oscillator isn't doing its thing. Power to the antenna goes up when the switch is depresssed, but it doesn't come back down like it used to, back when it gave me a nice 10kHz square wave. Now I am wondering if the chip is a 555 timer that is for some reason malfunctioning...
Many thanks for any help.
Dave