Bottom Coil Short Issues (EVOD, ProTank, Viva, etc.)

A Defective Head

I filled a brand new Viva BCC Mini today and found that my ZMAX went into short circuit protection when I tried to fire it.  No big deal, I knew it was a simple fix.  I've had a few EVOD and ProTank heads act this way, both right out of the box and after a few tank fills, so I thought I'd pass along a photo of a common problem with these heads.

The Problem

The issue is that the positive coil wire is making contact with the negative body of the base resulting in a short.  In this case, the ZMAX detected the issue as resistance being too low.  An initial test on a multimeter showed the correct 2.2ohm resistance and it wasn't until a little pressure was applied to the center post that the short happened.  Removing the coil head from the base revealed the problem.

Defective EVOD Head

As you can see in the photo above, the cause of the short is that the positive  wire from the coil is sticking out beyond the silicon gasket.  It's easy to feel the protruding wire when turning the head between your fingers.  When the coil assembly is screwed into the base, this wire may make contact with the outside of the tube, causing a short.

During the manufacturing process, the positive and negative coil leads are bent over the sides of the gasket and tube, respectively, to hold them in place when everything is assembled.  They should then be trimmed and pressed in flush with the tube, but that obviously has not happened.  Questionable quality control strikes again.

The Fix

Luckily, it's an easy fix.  Simply inserting your thumbnail between the bottom post and the gasket and then turning the head in a clockwise motion should be enough to push the wire back underneath the gasket.  Nail clippers wirk well for removing any excess wire.  It may take a couple of tries because of the springiness in the wire.  You should feel no wire protruding if you spin the head between your fingers now.  You've just recovered a head that seemed defective!

6 comments

  1. jake says:

    i can see the wire, but it really is just a super tiny nub, can barely feel it as i run my finger over it. i cant imagine being able to cut it down any more than it is, or that it could touch the side of the bottom cap… still shorted right away out of the box. (kangertech protank 2).
    ohms were fine right out of the box… even pushed in on the head to check for possible shorting, still read 2.2. ohms. all ive got right now is a mech with a safe fuse in it…. so im gonna wait till i get a ego with some short protection to test out all my addys.
    you said though that youve had this problem occur even after a couple refills, which worries me greatly.
    in all the pics ive seen of protanks that short, the positive lead is always sticking out quite a bit,,,, far more than mine is… is it safe to assume something else is shorting? or should i cut it down a bit more so absolutely nothing is sticking out at all?

    (ill eventually rebuild it and see if it still shorts, but for now ive lost trust in kanger products).

    • Eric says:

      Ultimately, cutting it so that nothing is sticking out is preferable, but you’re right, that can be difficult. Fingernail clippers seem to work best. You can also try to bend that spur under the insulator a little. A little pressure with your fingernail or a dull knife will do it. Just be careful not to damage the insulator.

      It is also possible that you have something else shorting. The center pin of your device is a possibility. You may want to invest in an ohm tester like the Omnitester from Smok. A $15 device can eliminate a lot of the guesswork.

      • jake says:

        thanks. pulled out the center pin and hid the positive lead below it. fixed the short… constantly checking with my multimeter and it seems to be fixed.

        (you dont have to read on… just venting.)
        ..but a slew of other problems have arisen, including no air flow due to squishy grommet, so i loosened the center pin off it so it wouldnt block airflow.. plus it lowered the connection to my battery which it seems to have a hard time reaching.. then it flooded the battery connection… i had. just cleaned out the center tube, everything was nice and snug. …gurgle, flood, no airflow.
        grabbed my nail clippers and trimmed in the grommet making it thinner above the center pin, so it could maintain height and allow air flow. cleaned it up, everything snug… take the best two hits ive taken, gurgle flood….
        i believe i may have a counterfeit product. it has two airholes in the base as opposed to what i believe is supposed to be three.
        either way… ive got an kanger evod blister in the mail. hopefully that will be money better spent.

  2. zach says:

    Great solution! As soon as that wire disappeared my unit became active once again! Cheers,

  3. cabsneezy says:

    Thanks so much. I was taking a wick out of my Evod and was wondering why it wasn’t firing. This helped me repair it.

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