Need help with VV board from MV

[AzPlumber]

I recently bought two of MadVapes VV boards rev 2. Put them both together yesterday and they both worked on a bread board so I threw them into their seperate enclosures. One works great (my wifes thankfuly) and the other is not doing so well.

It is in a plastic box with two 14650's 1050mAh with a 3 amp switch (don't need 3 amp switch but looks good) and a led when it fires. At first it worked great, fired it a few times with the meter to set voltage and then a few times with a carto and then it quit. I took the batteries out and checked them, they are ok but when I put them back in it works for one fire and then stays on until i pull the battery or the batteries protection shut the power off. Same thing every time, pull the batteries for a few minutes and it will work for one fire before it stays on. Is something heating up in that short time that puts the regulator into the on mode? Might be getting worse just checked it again (no carto in it) and the reg is still stuck on after 10-15 minutes.

 

[hoogie76]

Sounds more like battery protection kicking off. What atty or carto and at what voltage are you trying to run at? Have you tried different batteries or making sure they are fully charged?

When it stops, leave the batteries in the mod and test the voltage of each battery and see what you're getting. Just some suggestions..

hoog

 

[AzPlumber]

Tried differant batteries and yes when it shuts down it is the battery protection and I can deal with that. The problem i don't understand is the regulator stays on even after pulling the batteries out and no catro/atty. (Dual coil 2 ohm)

Hoog, Any suggestion on where to start looking for the issue. I have check for shorts and can't find anything out of whack.

 

[AzPlumber]

Sorry got a call and forgot to add that it is set at 4.5 volts. Just looking for suggestion before I take it out and put it on the breadboard

 

[hoogie76]

hmm. there's only 1 thing that can turn it on in theory and that is higher than 1.2 volts being applied to the control pin. I'd start there and see what the voltage is when it's on. If it's 0 volts, could bea defective regulator. R1 to ground keeps the control pin tied low otherwise if that pin floats it can be unpredictable and the reg can turn on by itself randomly. Take a peek at the control and see what it's doing when staying on.

hoog

 

[AzPlumber]

Thanks Hoog, I will check out the control pin area first. Let you know what I come up with when I get the time to check it out. This can't be too difficult, it's just a tiny little water heater right.