Nixie display problem - OT (!)

[Maximilian Hohmann]

Hello!

This is almost completely unrelated to calculators I'm afraid, but maybe a little bit.

My pretty living-room nixie clock stopped working some days ago. Instead of what it should display there are only some flickering "half-numbers" and nothing much else. I have some other stuff with nixie tubes (calculators and multimeters) which either work or don't work, but I haven't seen this kind of fault before. The manufacturer unfortunately disappeared, the website and e-mail address from the instruction manual are disconnected as well as the phone number. The clock must be from the early 2000s, at least 15 years old. So far I have measured the tube voltage which is 140V - this seems a little low, I would have expected 170 or 180V.

Does by chance anyone have an idea where I could start troubleshooting? The PCB is quite modern with mostly surface mounted parts, so probably not a lot I can do there...

Regards
Max

[Zaphod]

If you have other Nixie tube products , then you should first proof-test all the tubes.

It’s not clear from the photo, but some look a little sick.

As for voltage, initial strike voltage would be in the order of 170-180v, but normal sustain voltage could well be ~140v

You mention smd components , if this includes caps then these could well be your culprits based on the age.

I repair Electronics for a living so let me know if I can be of any help.

[vk6ti]

170 - 180 seems a tad high. I have had good
Success with nixies around that size with 110 - 130v

[Paul Berger (Canada)]

Some of those tubes appear to have blackened somewhat, that is normally a result of too much current, and is not reversable. The specs for most tubes are still available in various places, Sphere Electronics has posted specs for some tubes on their site, and if you can tell me what the tubes are I can check my collection of data as well.

Paul.

[Maximilian Hohmann]

Hello,

thank you all for your replies so far! The tubes are ZM1080 nixies. As they began to darken some time ago I bought some replacement ones, so far I could only find four new ones. Originally I wanted to wait until I have the complete set of six tubes before replacing them all together. In the process of replacing the tubes I will also try and replace all capacitors that are accessible to my soldering skills (I am not equipped to work on SMD parts). If all else fails I may have to send it to a professional (thanks Zaphod for your offer)!

Regards
Max

[Paul Berger (Canada)]

Data sheet for the ZM1080 can be found at http://www.tube-tester.com/sites/nixie/d...082_01.pdf and it states min supply voltage is 170V.

Paul.

[Zaphod]

(09-30-2018 12:09 PM)Paul Berger (Canada) Wrote:  Data sheet for the ZM1080 can be found at http://www.tube-tester.com/sites/nixie/d...082_01.pdf and it states min supply voltage is 170V.

Paul.

Yes, but look further into the data sheet (the next page) and it states ‘maintaining voltage’ (what I callled sustain voltage) is,as I stated: 140v

[Paul Berger (Canada)]

(10-01-2018 06:27 PM)Zaphod Wrote:  

(09-30-2018 12:09 PM)Paul Berger (Canada) Wrote:  Data sheet for the ZM1080 can be found at http://www.tube-tester.com/sites/nixie/d...082_01.pdf and it states min supply voltage is 170V.

Paul.

Yes, but look further into the data sheet (the next page) and it states ‘maintaining voltage’ (what I callled sustain voltage) is,as I stated: 140v

Sure but when some of the digits are constantly changing and may even be multiplexed I would think you would need to be nearer the striking voltage. In any case voltage in the range of 170 to 180V is not going to hurt the tubes as long as the current is controlled.