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(ACTUAL QUESTION IS AT THE BOTTOM)

I am a beginner in electronics and am learning more day-by-day to my best. I first got interested in Nixie tubes a few years back, so those are what I play around with, as they sparkef my curiosity.

I have been using this circuit I came up with:

enter image description here

And it has been working fine; all five 74141's I have had been working until late.

But I have found that, for some reason, when I had started using some new breadboard I had bought, that, suddenly, the circuit did not work. I removed it all and put it back together on my old breadboard and found that it did the same; all of the digits would be lit up at the same time save for one or two and would barely flicker. I did not think to swap out the 74141 for some of the other ones I havhavbut instead I decided to swap the tube for some LED's as I have before done using the same layout; all of the anodes connected together, sharing one common resistor:

enter image description here

It was at this point I saw that a handful of the LED's barely lit, others cycled through my test program, but LED #6, on pin 10 of the 74141 stayed on no matter what. Frustrated, I undid the entire circuit and redid it still the same thing. I have no idea why, but I decided to swap out the 74141 for another; it works perfectly; testing both multiplexing and just normal half-second cycle through, as should be expected.

QUESTION:

Exposition out of the way, IS THERE ANY WAY I COULD HAVE DAMAGED IT WITH MY CIRCUIT? Or perhaps just something random with the IC itself; it's not old (it's datecode is 1540--fortieth week of the 2015.) Some are still producing the K155ID1 in Russia for some reason. Perhaps dropping it? Or accidentally swapping the VCC and GND for it?

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    \$\begingroup\$ @MarcusMüller Ah youngsters. The Nixie is a fat round iphone screen that only displays one digit at a time in orange, and has a separate wire for each possible digit. Next weeks episode: Mr Baudots mechanical twitter machines \$\endgroup\$ – Henry Crun Aug 12 '18 at 10:41
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    \$\begingroup\$ By the way, excellent debugging. (you should, though, add a resistor to every single LED: else, the more LEDs you turn on, the less bright the individual LED becomes. \$\endgroup\$ – Marcus Müller Aug 12 '18 at 10:43
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    \$\begingroup\$ Also, make sure that you've read the datasheet of your IC! There's a hard limit on how much current you might sink into each pin, and I'm not sure your LED setup respects that (and yes, you can damage an IC with that). \$\endgroup\$ – Marcus Müller Aug 12 '18 at 10:46
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    \$\begingroup\$ If you accidentally shorted the 180V or the anode to the output pins, it probably wouldn't like it. My nixie driver only needs 60V transistors, 74141s might have a fairly low voltage capability too. (but I don't know much about them) \$\endgroup\$ – Henry Crun Aug 12 '18 at 10:50
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    \$\begingroup\$ Allright. Yeah, it might be on the low side, but it depends on the type of Nixie you have of course. If this is what your Nixies need, then you're allright. Besides, I think, if you've used 10k, then that's probably not the reason why your 74141 blew. Just checking :-) \$\endgroup\$ – MartinF Aug 12 '18 at 12:25
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You may be interested that you can just use npn transistors. This arrangement lets you use 7 pins to drive all 10 nixie digits. Off bases must be driven low. On a pcb, this is just 5 dual BC846 transistor packages.

schematic

simulate this circuit – Schematic created using CircuitLab

It is possible to drive 10 digits with only 6 pins, but 6 resistors are needed.

ignore(i.stack.imgur.com/2vAjU.png)

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  • \$\begingroup\$ You can even use MPSA41s which are cheap and are rated for 300V so you can turn any tube off completely (for blanking leading zeros, for example). \$\endgroup\$ – Spehro Pefhany Aug 12 '18 at 14:56
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    \$\begingroup\$ Indeed. Using a high voltage transistor should allow 4 pins to control all 10 digits. Interesting that they have really low min gains (25@1mA). xx5551's (VCE=160V) seem more normal (80@10mA) \$\endgroup\$ – Henry Crun Aug 12 '18 at 20:45

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