I recently put together a gra and afch nixie tube clock kit and everything works fine except that whenever the 1st digit in the groups of 2 tubes is a 5 every digit in those 2 tubes lights up. I figured there was a short in the HV5122PJ chip but I resoldered it and I am still having the issue.

 

Is there a circuit diagram available?

 

So the tube in the middle to the left is supposed to show 5, yes (got confused by the 5 on the left)? Which tubes do you have? Z573M?

 

Here are some links:
https://gra-afch.com/
https://gra-afch.com/catalog/nixie-...sembled-for-4-6-8-tubes-diy-arduino-no-tubes/

It appears to be the NCM109v1.1 and this might be its schematic:
https://gra-afch.com/downloads/sche...3xx-universal-control-board-for-nixie-clocks/

My suggestion is to contact the vendor/manufacturer and ask about that problem

 

Hello,

It looks like leakage of currents, as more numbers in the same nixie are activated.
It can be there is a problem with the nixie driver.

Bertus

 

I recently put together a gra and afch nixie tube clock kit and everything works fine except that whenever the 1st digit in the groups of 2 tubes is a 5 every digit in those 2 tubes lights up. I figured there was a short in the HV5122PJ chip but I resoldered it and I am still having the issue.

IMHO I would actually suspect a logic error, or code got corrupted during transport in the MCU, before I'd think hardware, based on what you've shown/described. Can the clock be reflashed remotely?

 

IMHO I would actually suspect a logic error, or code got corrupted during transport in the MCU, before I'd think hardware, based on what you've shown/described. Can the clock be reflashed remotely?

I believe it can be reflashed. I’ll look into trying that.

 

Here are the schematics for the 2 boards.

 

So the tube in the middle to the left is supposed to show 5, yes (got confused by the 5 on the left)? Which tubes do you have? Z573M?

The tubes are IN-8-2

 

Just finished the exact same clock. I would check to see if some of the pins on the back of "NX1" are touching the top of one of the two large caps. This allows a short between two pins and results in two or more characters to be lit at the same time. I had the same problem and removed some of the height of the pins on the back of "NX1" so no contact is made between the pins and the top of the caps. then used a small round disk of electricians tape to insulate the top of the two large caps. I had the 2 and 4 showing at the same time, this should fix your problem. This is kit has some got yah's along with a few other issues. Hope this helps.

 

Just finished the exact same clock. I would check to see if some of the pins on the back of "NX1" are touching the top of one of the two large caps. This allows a short between two pins and results in two or more characters to be lit at the same time. I had the same problem and removed some of the height of the pins on the back of "NX1" so no contact is made between the pins and the top of the caps. then used a small round disk of electricians tape to insulate the top of the two large caps. I had the 2 and 4 showing at the same time, this should fix your problem. This is kit has some got yah's along with a few other issues. Hope this helps.

I did have an issue with that as well I just placed some insulating tape on the tops of the capacitors so the pins wouldn’t make contact.

 

Hello,

It looks like leakage of currents, as more numbers in the same nixie are activated.
It can be there is a problem with the nixie driver.

Bertus

Burtus is on the right track. If it is not a logic error then it would be leakage, either inside the tube or in the associated circuits. So the first thing is to exchange tube positions and see if the problem stays in the same position, or follows the tubes. Neon indicators are quite high impedance devices and so it may be that the resistor array associated with those sockets are incorrect.