Help with IV-12 VFD Clock "Jenny"

Hello! I'm new to the forum and to Nixie builds, and not quite an electronics expert, but pretty well experienced with electronics assembly and soldering. In other words my work is neat and careful, but I'm not savvy enough to troubleshoot circuits if something isn't working quite right.

And I have a situation like that now: I've built the IV-12 "Jenny" clock (from the wonderful nixiekits.eu) and it's not a total success. All functions are working correctly, but the actual number display doesn't look right. The "unused" segments for each digit, which should be "off" or near dark, are slightly lit, and flickering a bit with the changing numbers. This makes the clock quite difficult to read, and comparing mine to the photos and video I've seen of this clock, I'm sure it isn't working right.

The effect looks worse in the photo than it really is, but you get the idea:



I have checked my work again and again, including placement and orientation of every component, and every step of the build instructions. The voltage tests in the instructions were all perfect. I can't find any poor solder joints or accidental bridges. Now I'm out of things to check, so I turn to you here for help! If anyone can suggest anything to check or try, I would appreciate it very much.

Thanks,

c.

Thanks very much for the suggestions!

To my astonishment (and no small amount of embarrassment) I discovered I had in fact installed RN2 the wrong way around. I am completely amazed to see that I had missed this again and again! (This does terrible things to one's confidence as a builder...)

But it's good news to have found the (likely) cause. Unfortunately I wasn't able to remove the thing without destroying it, so I've ordered a replacement and will follow up here after it gets here and I've installed it.

c.

Hello,

yes I'm also here. It looks that all gates of the tubes are not correct tied (via RN2) to GND when not accessed through IC7.
Try the following: First disable the leading zero suppression so that all tubes are active. Than shorten Pin 1 from IC7 to Pin 10 = short circuit to GND. This should completely disable the most left hand tube.
If the tube is not completely turned off than there's a fault on IC7 or RN2. Do not direct short ciruit the gate (or the corresponding output Pin 18 of IC7 to GND) as the source driver IC7 will be overloaded.

Fixed! RN2 replaced, right way around this time. The clock works perfectly now!

Thanks again for the help. I love this kind of international community support experience, that never could have happened before the internet. We live in a pretty cool time.

c.