Ok nice one mate, It would appear that my 'blown' 555s are not really blown at all, it just started working again, for no apparent reason.
I just Cant understand why this is.
A 555 has a momentary power supply current of 400mA when its output switches. A bypass capacitor is needed to hold up the voltage to the IC while the battery voltage is being killed. Anything elese using the same battery will also be starved of supply voltage when the output of the 555 switches, unless a bypass capacitor is used.
Ok nice one mate, It would appear that my 'blown' 555s are not really blown at all, it just started working again, for no apparent reason.
I just Cant understand why this is.
One old trick for intermittent operation is to go back and briefly touch a hot soldering iron to each joint. Sometimes a cold joint will cause lots of problems.