awsum140

Don't forget to check the 510 itself. A weak spring or bad center pin,not enough travel or too short, can give you real headaches like this.

1 milliamp at a nominal 4.1 volts is 4 milliwatts. Not exactly heating your mod to any measurable degree. Stop blaming the board. You apparently have a bad connection between the board and the 510 or a bad 510 connector. Start looking at that for a bad solder joint on the board, the ground lug not being tight enough or a bad solder joint there, or a weak center pin or a bad solder joint there. Given that your problem is occurring with multiple, different, atomizers the problem is, more than likely, a bad connection to the atomizer itself and not a problem with the board. The board only "knows" what it "sees" and it isn't seeing a solid, good, connection. I have, and many, many people have, multiple 250Cs and have no problems with incorrect resistance readings. I'm not saying it's impossible but I am saying it's extremely unlikely. What gauge wire did you use between the board and the 510? Is it silicon insulated wire? I believe 14 gauge is the recommended gauge.

How did you determine it was not charging? The 250C stays "asleep" while charging unless charging display is turned on in a theme, I think. The USB connection, for Windoohs to see it, needs a data connection, not just power. In any even fooling around with a PC USB port like you are is crazy. Mobo or port can be too easily damaged. Buy a multi-port wall war as has been suggested and forget the kludge of eight off a single USB connection. A single USB port, on its best day, would smoke with the load to two 250Cs charging, let alone eight. I'm a kludger, too, but wouldn't do that kind of kludge.

Not having things in my hand, this is only a guess. From what you're describing I'd say the 510 on your mod is the culprit. If you can, make sure the center pin of the 510 on the mod has some free travel and isn't sticking "down" or otherwise too far down in the connector.

FWIW - I've installed DNA75 boards into ERM, DNA200/250, enclosures with no problems. Screen, fire, up, down, mounting holes all line up perfectly plus you have the extra space at the bottom since, as Wayneo says, there's no JST connection because it's a single cell device. ft

A quality, temperature controlled, soldering station and 14 gauge is not problem at all. Tin the pad, tin the wire, and use silicon wire, a tiny dab of quality rosin flux on the pad and it's quite easy to solder effectively with a temperature controlled iron.

I'd suggest trying a simple, single wire coil made from only a TC material. You have not mentioned what atomizer you are using which can effect how stable the resistance remains.

I forgot to mention, thanks dw, that is in a dual coil tank so each coil is around .46 ohms.

I routinely wrap 28 gauge SS430 with six wraps on a 3.3mm mandrel and get around .23 ohms out of them.

No, not at all. Sub ohm coils can be run on unregulated mechanical vaporizers.

Short answer....The higher the capacity, real capacity and not some advertising guesstimate, the longer the usable run time and that applies to any device, mod, no matter what the battery configuration may be. Total capacity in watt hours is the important number to look at as well as the maximum discharge rate. A regulated device is a "mod", the circuit board and enclosure, not a tank or coil. Nomenclature is meaningful.

Let's see, I live in Southern New Jersey. It does get humid but no other board types have been effected. I haven't been near the ocean for a few years so no salt water problems. They all live inside the house so temperature swings might be from 85 for a high to 65 for a low. Carpets, especially during the summer, don't produce much static electricity. The nearest radio station is about two miles away and is only a "sunrise/sunset", 10Kw transmitter. I'll add that there has be no liquid inside any of the 75C mods, either. Given that only the 75C boards have failed in this manner, and all have failed in the same manner, it's hard to believe that any outside factor is involved. All of my other mods, from 40 to 250C , all seem to survive very well in the exact same environment.

I hate posting this because I love Evolv products, but I'm a little disappointed in the 75C. I've had three, in two different mods, fail since getting them last February. They've all failed in a similar fashion. The first one did the "white screen" thing first, then started going to sleep immediately during use, or shutting off in mid puff. It finally refused to turn on. The other two failed without the "white screen" problem but did the same sleep/shut off problem. Both mods are GL2s powered with dual, parallel, 20700s. Battery life, when they work, is outstanding but they just keep stopping working! What makes it a real PITA is that the board sled is glued into the case making it time consuming to take the board out for replacement. I am experienced in soldering and have built at least a dozen DNA mods ranging from DNA40s to DNA250Cs. Some of those were built from scratch rather than being pre-machined cases. All of them, with the exception of one DNA250, are still operating on their original boards while the 75Cs don't seem to last more than about four months of regular use. Has anyone else experienced this, or I am just "lucky"?

What you appear to have there is known as an Evolv Reference Model, the case used by Evolv when beta testing the DNA200. It is designed to take an 800-1000mah, 3S, LiPO pack. As retird said, AA batteries will not work and can be hazardous to try. While a DNA75 runs on a single LiPo battery, 3.7 volts nominal, the current demand is far in excess of what a AA battery can supply.

Heck, you spoiled the mystique.