Pinning down a short

[jock1092]

So I'm a little lost on this one and needing a touch of advice

Got a goon 1.5 clone with a broadside clone for 20700s (since I needed some of those batteries anyway why not add a new mech to the collection)

But a week in I have an obvious arc mark inside the rda, including a well tarnished deck screw that matches placement wise to the arcing

Sounds simple enough but it's turning out not to be

What I know (and have triple checked, starting simple)

Checked the coils

The coil reads exactly what I expect ( aliens at 0.18, vapes as expected)

Rebuilt and retested (same coils but fitted from scratch)

Neither my dna mods or ohm reader can find any issue - my wismec did throw a fit at one point with it though (I tired it on all my regulated mods after a rebuild to rule anything obvious out)

This happened when I ramped it up to 100w ( the coils are thin but can handle it, it's a standard build. I use)

So at this point I feel longer I've tried everything - I can't find any repeatable issue but I know it's happened /happening without any noticeable effects

This annoys me because I want this rda on its matching device, but I also don't want a shorting atty anywhere near a mech

Any ideas on finding/fixing it beyond what I have already tried?

 

[speedfreek67]

If it's on the positive post have you checked for a crack in the insulator?

 

[speedfreek67]

And if it's on the negative post have you checked for a crack in the 510 insulator?

 

[jock1092]

And if it's on the negative post have you checked for a crack in the 510 insulator?

Might have helped to say its between the posts and the barrel if that makes sense

Best way to explain would be between the post screw and the airflow

 

[jock1092]

Decided to update with a picture

Blue screws (not something I like painted) with the last one stripped of its colour

That dark spot is actually black with a shiny centre, making me think it's arcing that caused it

Currently running it on my dna to try and determine it it's actually shorting or a one of arc, but it seems too large to be a one off

 

[Bazz_74]

If you've tried it on all your regulated devices are you sure it's a short? most good regulated devices will detect a short and refuse to fire, could it just be a scorch mark from a hot coil?

 

[speedfreek67]

Well, I can see that it is just above the single airflow slot, and considering you are using dual coils, that would indeed be right next to where the outside of the post (and the discoloured screw head) sits next to the top cap.

The space between the outside of the post and the inside of the AFC top cap is very small on the Goon 1.5, so if your AFC has a burr sticking out or some other slight defect that closes that space a little in that area, or if (as it kinda looks) the post clamp seems to overhang a little, I suppose it could arc, causing extra heat and burning the screw head?

 

[Cliffyboy1962]

Whilst not offering an actual solution, I wonder if it might be worth spinning the barrel 180 degrees to see if this arcing happens on the other side of the barrel. I dont know what exactly this would prove but if it didn't do it anymore, this would surely offer a clue as to what is going on.

 

[jock1092]

If you've tried it on all your regulated devices are you sure it's a short? most good regulated devices will detect a short and refuse to fire, could it just be a scorch mark from a hot coil?

That was my first guess but lining it all up it ends up next to the post, but only the wismec claimed it was "low" and even then only once

 

[jock1092]

Well, I can see that it is just above the single airflow slot, and considering you are using dual coils, that would indeed be right next to where the outside of the post (and the discoloured screw head) sits next to the top cap.

The space between the outside of the post and the inside of the AFC top cap is very small on the Goon 1.5, so if your AFC has a burr sticking out or some other slight defect that closes that space a little in that area, or if (as it kinda looks) the post clamp seems to overhang a little, I suppose it could arc, causing extra heat and burning the screw head?

I might try just filling it all back to smooth and see if it comes back, if there is any burr or super close bits that might fix it

For now I might keep it as a non mech rda until I'm sure its all good