Leakage current from USB killing the fuse?!

[vapealone]

Mad Scientist said:

Well seems the good news is if it was a design issue with the board you'd see more folks reporting the issue on this forum.  You seem to be the one and only.

I hear you, don't fully agree though

I agree that there are too many blown fuses around and I haven't see rock solid evidences on modder failure or on anything else.
It could be this or that or whatever.

And that is exactly why I pushing on the option that the USB can short out some circuit if forced. 

It was a very 'lucky' find* and hard to mimic it for testing. I have already stopped experimenting with it as I don't want to deliberately damage neither the board board my cables.

But it was a real, live short.

The possible outcomes of this short or the actual location of it (on the board or in the male/female socket itself) is still unknown and no one really knowledgeable bothers to look at it. (John just explained normal conditions above that doesn't hold if you short out the designed way)  

I have actually planned to pushing on until someone checks on all the options, but getting tired.
If this is the hidden booby trap (a specific male plug+applied force+preheat power) I know how to avoid it in the future and I will.


*For how hard and lucky it was:
My mod was opened up, tethered and some atomizer on. As I posted somewhere it was tilted supported by the USB cable and I actually checked the temperature on the board when I accidentally pressed the whole lot and the Atomizer Analyser came to life. At first I thought that I had some contact problem on the back, slowly circling toward the usb
But I still don't know if it is actually the USB or not. That is the closest I could get.

[Mad Scientist]

Might well be that there's something going on with flexing the specific board you have or possibly something more. I don't know how much time you want to spend hunting it down, but you could replace the fuse and then try to rerpoduce the issue. If the fuse blows when you flex the board, you've found the source of your fuse issue. Evolv would have to examine the board for comparison to determine if it's just that board or if there's anything more to it. Looking at the board, I don't really see how the USB connector could touch anything but maybe flexing your board had an effect.

[vapealone]

Mad Scientist said:

Might well be that there's something going on with flexing the specific board you have or possibly something more. I don't know how much time you want to spend hunting it down, but you could replace the fuse and then try to rerpoduce the issue. If the fuse blows when you flex the board, you've found the source of your fuse issue. Evolv would have to examine the board for comparison to determine if it's just that board or if there's anything more to it. Looking at the board, I don't really see how the USB connector could touch anything but maybe flexing your board had an effect.

Well, like I have said, my hunting is over. I couldn't get any closer.
If Evolv will check/it flex it when they get it back, so be it.

But if it wasn't over, I would start from the other side

The only thing I can tell for sure that AA can work. So I would look at this function first checking how it can possibly be powered up, which circuit(s) must be closed etc. Than check all the possible bridging ways/spots that can close it  w/o fuse)
Than check the circuits powered by USB close enough for some mechanical shorting if forced.... etc

[Mad Scientist]

vapealone said:

Well, like I have said, my hunting is over. I couldn't get any closer.
If Evolv will check/it flex it when they get it back, so be it.

But if it wasn't over, I would start from the other side

The only thing I can tell for sure that AA can work. So I would look at this function first checking how it can possibly be powered up, which circuit(s) must be closed etc. Than check all the possible bridging ways/spots that can close it  w/o fuse)
Than check the circuits powered by USB close enough for some mechanical shorting if forced.... etc

No worries but we must be on different wavelengths. It is supposed to power up on USB and potentially fire and read resistance and do all the stuff it does, but at obviously reduced power. This is not a fault or bug. The important failure mode is that blown fuse and I'm curious as to what caused that. If the board is doing what it's supposed to, that "can't" happen.

[vapealone]

Well, on my wavelength your board didn't read atomizer resistance w/o battery power plug connected and, strictly on this wavelength, kinda think that you couldn't continuously fire the mod up even on 1W settings when only charging cables attached
Of course, it is possible that it works if you connect (-) for ground but don't connect (+) (modelling a blown fuse)
I might try it one day. I want to hook up an external fuse anyway, so I can check when the replacement board is here (and find room for the extra fuse)