Help with Gra and afch nixie tube kit .

Thread Starter

Jrok96

Joined Jan 14, 2018
12
Hello all,
I recently got a in-14 nixie tube kit from eBay.
I have it built and have double checked the soldering . But as always of coarse the problem probably is with my soldering. There were also a few components that i wasnt 100 percent sure that i had turned the right way .considering all i had to go on was a youtube video.The clock turns on and the leds light up and the little musical tune play but am not getting anything from the nixie tubes themselves.
I have 5v ,12v, and 3v at all the test points on the board but the 170v is only getting 53v?
I can link the diagram for the kit I have but it's hardware revision 2.0 (latest) for in-14 tubes . I can also post pictures of board .
Any ideas how to test and get this working ?
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
That voltage reading is at the test point marked on the circuit diagram. I also measured pin 1 on all 8 tubes and got the same reading .
I turned the adjusting pot at one point while constantly testing voltages and they maybe changed by .1 v . I was considering it within margin of error .
Originally I had 9v power supply that came with the arduino mega rather than a 12v one required. The 12v points were only reading 8v and the one that's supposed to be 170v was only 41. I thought for sjre thos woukd ha d been the problem but unfortunateky it wasnt .
Here are the other symtoms on the board but it may be completely unrelated . The number 2 rgb led only works when cycling on red . When the other colors are commanded on it is completely off .I went to test that rgb but realized by The diagram it seems to be network controlled rather than each ground controlled individually . So wasn't sure how to . Again this could be unrelated to the nixie tubes
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
Ok when I test across the resistor (like for voltage drop) I get .001 .
Both sides of the resistor have 53v jen measured individually.
 

LesJones

Joined Jan 8, 2017
2,419
What is the voltage between ground an pin 3 of the LM3488 ?
WITH NO POWER applied to the unit what is the resistance between the 180 volt test point and ground ? Measure it twice reversing the meter leads between the two tests.

Les.
 
Last edited:

neonstrobe

Joined May 15, 2009
74
What the members are enquiring about is whether your 180V works properly. From your description, it does not, but we need to know if there is something loading the supply (in which case there may be a wrong connection almost anywhere, as I imagine that the only parts connected to the 180V are the capacitors and nixie resistors; and the nixie tubes won't load the HV line until the voltage is about 150V (that is why they are not lighting up) or if the 180V inverter does not work (but if you are measuring 53V that suggests that there is something loading the supply).
Is there any component you can see getting hot? This voltage may be due to a transistor somewhere breaking down.
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
Make sure the voltage across R51 is zero (well less than 16mV).
What is the voltage between ground an pin 3 of the LM3488 ?
WITH NO POWER applied to the unit what is the resistance between the 180 volt test point and ground ? Measure it twice reversing the meter leads between the two tests.

Les.
Voltage at pin 3 is 1.1v
Ohms from 180v to ground varies each time I lift the leads off and put back on from .45m to 1.7m ohms . I tested with leads reversed and got the same results.
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
What the members are enquiring about is whether your 180V works properly. From your description, it does not, but we need to know if there is something loading the supply (in which case there may be a wrong connection almost anywhere, as I imagine that the only parts connected to the 180V are the capacitors and nixie resistors; and the nixie tubes won't load the HV line until the voltage is about 150V (that is why they are not lighting up) or if the 180V inverter does not work (but if you are measuring 53V that suggests that there is something loading the supply).
Is there any component you can see getting hot? This voltage may be due to a transistor somewhere breaking down.
Unfortunately nothing seems to stand out or get hot to the touch, or with a IR infrared thermometer
 

BobaMosfet

Joined Jul 1, 2009
893
Hello all,
I recently got a in-14 nixie tube kit from eBay.
I have it built and have double checked the soldering . But as always of coarse the problem probably is with my soldering. There were also a few components that i wasnt 100 percent sure that i had turned the right way .considering all i had to go on was a youtube video.The clock turns on and the leds light up and the little musical tune play but am not getting anything from the nixie tubes themselves.
I have 5v ,12v, and 3v at all the test points on the board but the 170v is only getting 53v?
I can link the diagram for the kit I have but it's hardware revision 2.0 (latest) for in-14 tubes . I can also post pictures of board .
Any ideas how to test and get this working ?
Seriously, I think you need to post some clear shots of the board. The fact that you are having irregular voltages, suggests you have one or more ground-loops. Without a relatively stable, universal ground, the difference between what is ground and what isn't can be anything from way too high to within a few volts.

If you have a bad set of soldering, or you have solder connecting things it shouldn't, you're going to actually have a devil of a time doing anything with a DMM, because of the nature of how energy is oscillating through the whole circuit. And you absolutely must be very careful of how much voltage and or current you introduce to a circuit while testing, or you can ruin gates in TTL chips, diodes, and other things.

What you describe sounds like a ground issue.
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
I can take specific close-ups of any of the components or sections if it helps. And yeah unfortunately I don't have an oscilloscope .
 

LesJones

Joined Jan 8, 2017
2,419
Re your results in post #12 The voltage at pin 3 on the LM3488 should be 1.26 volts. As it is below this it means that it will be trying hard to output more voltage. The reason for the low initial resistance readings is due to the capacitor C15 having to be charged by your multimeter. If the reading stabilises at 1.7 meg then there is no short. The theoretical reading should be between 1.5 meg + 4.7K (1504.7K) and 1.5 meg + 4.7K + 10K (1514.7K) depending on the setting of R58. The fact that the reading is a bit higher than expected is probably component tolerances. I think the fault is in the step up regulator or D14 is drawing current at a lower voltage than it should do. I would be tempted to temporally with a 1K resistor so measuring the voltage across it would give us a way to read the current through D14.

Les.
 

Thread Starter

Jrok96

Joined Jan 14, 2018
12
Hey guys thanks for all the help. seriously! . I began going over the entire 180v line again and even tho the lm3488 @u6 looked like there were no shorts it showed .2 -.4 ohms between two sets of legs .
I once again broke out the desoldering braid and pretty much soaked up all tje solder from the top of the pins .The .2 ohms became thousands of ohms so I plugged in the power and the damn tubes finely began working .
All in all this project was pretty enjoiyable even tho I was pulling hair out and bugging you guys trying to figure out why the voltage was so low .I really appreciate you guys trying to help track this down even tho u couldn't physically put your hands on it.

So in the end it actually was a problem with the step up reg. @LesJones!
 
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