Have you got a Plasma ball to hold it to? If air has entered in you might see a very faint blueish glow if you turn off the surrounding light.
What does the getter flash look like, like a mirror or is it gone completely, or has it gone white? I have seen a few Nixies where the Anode wire has come lose at a welding spot, can you see if something similar has happened to your Nimo with any of the wires or the Anode connection - if so you might smack it gently against your palm to see if the wire reconnects enough for it to work again? /Martin On Saturday, 3 October 2020 23:35:35 UTC+2, jörg wrote: > > Hi Gregebert, yes, I've checked the tube several times. The cold > resistance is about 2,1 ohm, which is identical to the other tubes. > Just swapped the tube with a running one on the same driver board. Sadly, > no function at all. Under a microscope, no crack is visible. > > I've made a short video to show the difference between a neon-nixie and a > nimo crt-tube and a neodym magnet (very small one.) > https://www.youtube.com/watch?v=JJytnrvTy3Q > > gregebert schrieb am Freitag, 2. Oktober 2020 um 19:25:40 UTC+2: > >> Jorg - Regarding the dead tube, have you compared the filament resistance >> of the bad tube to the others ? >> >> NIMO tubes have 2 parallel filaments, so if one is open, the resistance >> will be TWICE the value of a good tube. >> I think the cold resistance is around 3 ohms. >> >> If 1 filament is out, you can still get 5 numerals to work. >> >> I would be surprised if both filaments are burned-out, unless someone put >> way too much voltage on it, or the tube is cracked around the pins. >> >> If the filaments are OK, power-up the tube and make sure you get around >> 180mA of current. >> Then try varying the voltage between the filament and the logic driving >> the grids. If a grid is about 6 V more positive than the filament, you >> should get a numeral to turn on. >> >> On Thursday, October 1, 2020 at 1:44:20 PM UTC-7 jörg wrote: >> >>> Short update of my nimo project. >>> I've got 5 tubes running. The sixt is unfortunately DOA. >>> The tubes filaments are driven with three power supplies, with soft >>> start IC (load switch). >>> So the filament gets started very smooth. >>> I've made some experiments with multiplexing the tubes. >>> Which work nice, using the method described in the manual. The bias >>> voltage is changed for every tube, that should be on/off. >>> In the actual approch, I'm using direct driving the tubes via 74HC595 >>> shift registers. Got a plenty of problems at the beginning. >>> The power and signal lines for the 595 were messed with switching noise. >>> Some caps did the trick. >>> Really nice to view the working tubes. >>> >>> Video: https://www.youtube.com/watch?v=JbwfZhYhnlo >>> >>> jörg schrieb am Mittwoch, 15. Juli 2020 um 18:01:18 UTC+2: >>> >>>> I‘m using Eagle to layout. >>>> It takes time for me to feel comfortable with it. >>>> And Fusion360. >>>> >>>> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/22f467bf-d4ba-477f-a171-abd207afaa54o%40googlegroups.com.
