Show-n-tell UDS with a heatermeter blower short?

[AllenH]

First off, this is a cool forum, thanks for all the knowledge and info!

I've been building a UDS for almost a year now. Designed the charcoal box, grates, and other parts with Fusion360 and cut them out on a CNC plasma table.


I'm really close, but when I hooked everything up for my final test before burn, I found that the microdamper fan wouldn't turn on...

 

[John K BBQ]

That's one tricked out UDS! I wish I knew something about heater meters so I could help out! Hopefully another member will chime in soon.

 

[AllenH]

...so, I pulled everything apart and have found that I have a short on the blower fan circuit, but for the life of me, I can't find where it is! I've spent two nights now tracing and touching up solder joints, but if I touch ground, and the 5th pin on the RJ45 for the blower power, I get continuity

Here are a bunch of the pics from my circuit board, does anybody have an other ideas I can test?

 

[AllenH]

 

[Mitch_D]

Check out this thread? It has links to images of voltage test points. https://tvwbb.com/threads/new-build-blower-and-damper-not-running.83489/#post-924437
Did you clean flux off with isopropyl alcohol?

 

[AllenH]

Check out this thread? It has links to images of voltage test points. https://tvwbb.com/threads/new-build-blower-and-damper-not-running.83489/#post-924437
Did you clean flux off with isopropyl alcohol?

I had not run across that thread yet, thank you! Yes, I did clean off the flux with a toothbrush and isopropyl alcohol, but that digital microscope sure looks like there is some left on there.

I think I may have found the problem, these two capacitors both have solid continuity, not just the beep when checking with my digital multimeter... All of the other capacitors on the board do a quick beep, then stop with the test.

 

[AllenH]

Showing my electronic newbness here, that bigger one is an inductor and looks like it _should_ have continuity... so, maybe just the one capacitor is bad... I'll start with that.

 

[AllenH]

Pulled the capacitor off, now off the board it doesn't have continuity, but the traces do. Now, looking at the board under the capacitor, looks like I fried a trace and that's what's causing it to ground?

 

[MartinB]

I'll tell you right now you need to get that damper away from the side of the cooker. You are going to melt it. Put yourself on a elbow and a nipple and get it a few inches away. Before it melts it's going to warp and deform. After you have to print your first replacement one you'll understand...... I cooked one just from the heat of a lit chimney (hot) that was about more than a foot away... The breeze direction shifted and that heat started hitting the damper. It warped , and didn't work when I started the smoker running with the lit coals.

The heater meter itself doesn't like hot temperatures either. If it gets hot it will go wonky. You have to be careful how close you put it to something hot as well. Might have something to do with the thermocouple compensation.

 

[AllenH]

I'll tell you right now you need to get that damper away from the side of the cooker. You are going to melt it. Put yourself on a elbow and a nipple and get it a few inches away. Before it melts it's going to warp and deform. After you have to print your first replacement one you'll understand...... I cooked one just from the heat of a lit chimney (hot) that was about more than a foot away... The breeze direction shifted and that heat started hitting the damper. It warped , and didn't work when I started the smoker running with the lit coals.

The heater meter itself doesn't like hot temperatures either. If it gets hot it will go wonky. You have to be careful how close you put it to something hot as well. Might have something to do with the thermocouple compensation.

Thanks, I was going to see if I could get away with it that close. I did print in Carbon Fiber Polycarbonate, which has a higher melting point than PLA/ABS, but you're probably right, I should put a 90° and move it out.