Eleaf Pico weird behavior.

[Boeriemore]

Right, the battery slides down into the sleeve. At the bottom is a raised flat positive terminal.
The cap that screws down has the negative terminal protruding.
On fitting a re-charged battery, common sense tells me that the more the cap is tightened the better
the connection. Not so with my Pico. I screw the cap all the way until it is tight yet at no point does the display light up. I then start unscrewing it and at some point seem to hit a sweet spot then the display lights up. Later it may go out then by screwing the cap backwards and forwards I eventually reach that "sweet" spot again and the display lights up again. Absolute no logic in this.
I would love to have someone offer an acceptable explanation.

 

[Kuhlkatz]

I'm not familiar with the Pico's insides, but had a quick look at Daniel taking one apart. It sounds like a loose connection on the wire to the positive terminal, as it is spring loaded and angled at 90 degrees where the wire is soldered. Looking at the PCB and some of the grounding done on there, it might also be a possibility that the negative post is not kosher, but if it is that, pressure on the PCB from the fire button would likely also light it up.

Disassembly starts at around 21:00:

 

[Wayne Swanepoel]

yup, I would disassemble clean and check then reassemble.

 

[Boeriemore]

I'm not familiar with the Pico's insides, but had a quick look at Daniel taking one apart. It sounds like a loose connection on the wire to the positive terminal, as it is spring loaded and angled at 90 degrees where the wire is soldered. Looking at the PCB and some of the grounding done on there, it might also be a possibility that the negative post is not kosher, but if it is that, pressure on the PCB from the fire button would likely also light it up.

Disassembly starts at around 21:00:

I hope I'm not speaking too soon but here goes. I realize now that a terminal or thread can look clean and shiny yet be the problem.
First "low atomizer"display turned out to be the 510 thread. It appeared spotless but I used lemon juice on it and the problem was solved.
I read a post from someone with the identical battery connection problem I had/have. All replies suggested cleaning the cap's thread.
Everything appeared like new to me but I tried lemon juice on the cap's thread, the sleeve's thread, and the terminals.
I fitted a battery and screwed the cap up tight. The display came on and has been on all afternoon. I realize now that a visual inspection
counts for nothing. Here's to my lemon juice.

 

[Kuhlkatz]

Holding thumbs that the solution is/was just as simple as cleaning the threads & terminals.
Now we know for future reference.

 

[thaabit]

I hope I'm not speaking too soon but here goes. I realize now that a terminal or thread can look clean and shiny yet be the problem.
First "low atomizer"display turned out to be the 510 thread. It appeared spotless but I used lemon juice on it and the problem was solved.
I read a post from someone with the identical battery connection problem I had/have. All replies suggested cleaning the cap's thread.
Everything appeared like new to me but I tried lemon juice on the cap's thread, the sleeve's thread, and the terminals.
I fitted a battery and screwed the cap up tight. The display came on and has been on all afternoon. I realize now that a visual inspection
counts for nothing. Here's to my lemon juice.

This is the 2nd time I hear lemon juice fixes vape related issues.
The 1st one was for a cure for vapers tongue and now cleaning threads and terminals
Is lemon juice the WD40 of the vape scene?

 

[Boeriemore]

Holding thumbs that the solution is/was just as simple as cleaning the threads & terminals.
Now we know for future reference.

It is better, but not perfect. It was fine throughout the duration of the battery's charge. I have just replaced the battery and screwed the cap closed but the display did not come on. I unscrewed it and started tightening it again and got to a point where it came on. Still holding thumbs.

Update: Problem returned after one day. I cannot believe that the threads require cleaning every single day. I also do not believe that the problem is linked to a possible bad connection at the bottom
because one time when display went off I gently touched the cap and turned it no more than a millimeter and the display came back on. That small movement of the cap surely could have no effect on any wiring by the positive terminal.
The mystery remains.

Another update: Problem solved. I roughened up the negative terminal with sand paper. It now works fine.