I did trace the logic level signal from the CPU to the anode driver -- it's good all the way up to the NPN and past that thru the voltage divider (although harder to see) to the base of the PNP. So while I am *fairly* certain the PNP is the culprit, I haven't ruled out a tube yet. Resistors ohm out good.
Terry On Friday, November 11, 2016 at 9:56:47 PM UTC-6, Dekatron42 wrote: > > You might already have tried the ideas below, or already know about them > but I mention them anyway as I have come across those faults. > > You should make sure that you load the driver properly, otherwise it might > not show its fault as small leakage currents will be present and show you > the wrong voltage levels. If possible you should disconnect the two Nixies, > you can do this by unsoldering the end of the anode resistor closest to the > nixies and hook up a known good nixie to the anode resistor, wiring one of > the cathodes to the same cathode on the nixies. This way you will know that > you have a known good nixie there and if it still fails it must be some > component in the driver chain, all the way back to the controller driving > the NPN transistor. > > You can also unsolder the resistor driving the base of the NPN transistor, > the end closest to the controller and then hook it up to any of the other > anode drivers, if the driver works then it is the controller. > > /Martin > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/6a0e4db1-0648-4a76-9b30-ce53529c15ec%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
