I'm hoping someone can help us troubleshoot. My daughters have been working on building the ice clock and every test was successful, but when it came time to get the tube to light up... no dice.
With the tube in place, here are the voltages we found:
-At R3 10.4v
-At D3 10.4 v
-At the ISP closest tab 8.7v
-At the ISP furthest tab 4.8v
With the tub removed, the voltages are:
-At R3 13.9V
-At D3 13.9V
ISP maintains the same voltages
We looked up this problem on the forums and tried jumping Q3, but no change.
We'd appreciate any advice! Here are some photos (I know the soldering job is a bit messy... I tried going over any possible weak joints and may have ended up with too much solder on a bunch of them).
Tube not lighting
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- tcymrot
- Posts: 5
- Joined: Mon Mar 09, 2015 10:35 am
Re: Tube not lighting
Here are three more pictures:
- tcymrot
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- Joined: Mon Mar 09, 2015 10:35 am
Re: Tube not lighting
Sorry, one more clarification... where I wrote ISP, I meant "IC3"... the regulator chip!
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: Tube not lighting
Do you get the beep on power-up?
On a few of your solder joints, the solder is balled-up around the pin. That sometimes means that the solder has not flowed well onto the solder pad. This guide has some tips on identifying and fixing these:
https://learn.adafruit.com/adafruit-gui ... n-problems
On a few of your solder joints, the solder is balled-up around the pin. That sometimes means that the solder has not flowed well onto the solder pad. This guide has some tips on identifying and fixing these:
https://learn.adafruit.com/adafruit-gui ... n-problems
- tcymrot
- Posts: 5
- Joined: Mon Mar 09, 2015 10:35 am
Re: Tube not lighting
I'm afraid that any excess solder is a result of my going over the girls soldering... I can try retouching these again, but I don't think it is the source of the problem. We do get the beep on power up, and all other tests have the expected voltage. We jumped the Q3, and no change.
When we put the ground probe at the IC3 and touch the red probe to the wire leads on the vacuum tube we get fluctuating voltages, and uneven voltages depending on which side of the tube. Does this indicate anything in particular? Are there other tests we should be doing isolate the specific site of the problem?
When we put the ground probe at the IC3 and touch the red probe to the wire leads on the vacuum tube we get fluctuating voltages, and uneven voltages depending on which side of the tube. Does this indicate anything in particular? Are there other tests we should be doing isolate the specific site of the problem?
- adafruit_support_bill
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Re: Tube not lighting
So the processor is running, but the boost converter isn't boosting. Can you post a top-down shot of the component side so we can see all the components? Double check the orientation of Q2. The bridged pins should be adjacent to D3.
- tcymrot
- Posts: 5
- Joined: Mon Mar 09, 2015 10:35 am
Re: Tube not lighting
Thanks for your help with this... we double checked and Q2 appears to be oriented correctly. I'm attaching a few more top down photos. Any further meter tests we can run to isolate the source of the problem?
- adafruit_support_bill
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- Joined: Sat Feb 07, 2009 10:11 am
Re: Tube not lighting
That all looks correct. The boost converter is driven by Q2 which is controlled from pin 12 of the main processor. If you have any access to an oscilloscope, it would be helpful to see if there is signal on pin 12. A meter reading would be less conclusive, but I'd expect to see something less than 5v on that pin.
Looking at the solder-side photos, the solder joints where Q2 connects to D3 look a little solder-starved. I'd touch those up a bit.
Looking at the solder-side photos, the solder joints where Q2 connects to D3 look a little solder-starved. I'd touch those up a bit.
- phild13
- Posts: 247
- Joined: Mon Sep 10, 2012 1:05 pm
Re: Tube not lighting
The tube header is soldered onto the tube board backwards. Bill can tell you what you need to do from this point forward.
- adafruit_support_bill
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Re: Tube not lighting
Well spotted PhilD. I was focusing on the low boost voltage.
A reversed header can be fixed with some patience. If you can get access to a hot-air soldering station, you can probably get it off intact. Otherwise, I'd de-solder it pin-by-pin (you can just pull them out through the plastic spacer). You can clean up any stray solder with some solder wick and/or a solder-sucker. Then replace the header with a piece of 2x right-angle header.
https://www.adafruit.com/products/1541
A reversed header can be fixed with some patience. If you can get access to a hot-air soldering station, you can probably get it off intact. Otherwise, I'd de-solder it pin-by-pin (you can just pull them out through the plastic spacer). You can clean up any stray solder with some solder wick and/or a solder-sucker. Then replace the header with a piece of 2x right-angle header.
https://www.adafruit.com/products/1541
Please be positive and constructive with your questions and comments.