Hi eric,
i never test the test probe on 0 volt. Why not?
Basically, i was using an extra red led to connect to 7410> it does light up the both the 2 red leds. I don't understand this sentence.
I'm not sure if the capacitor volatge was affecting the 555 timer. What is the ideal volatge to be used? Basically, when i d/c the cap, with resitor on, the red light is on.
See my previous post re the cap voltage. What red light are you refering to? The one connected to U3/12 or the one connected to Eric's logic probe?