[250c 2 cells. Will it charge without jst?]

You also need to set the number of cells, using eScribe, in the configuration for the mod and save that to the mod.

[Where to purchase boards in the states]

AlpineTech is another reliable source.

[Can't unlock my DNA250C mod anymore (Dovpo Top Gear)]

Try disconnecting/removing the batteries and leave it completely unpowered overnight.  I had a similar problem with a 100C and doing that cured it.  As with everything YMMV.

[A problem and a fix]

I want to share this in the hope that it will help someone else.

I have two DNA100C's and one got knocked off an end table.  It took a hit to the screen that resulted in a black blob in the center of the screen making it impossible to read what was going on.  I have replacement color screens, so time for a replacement.

Took it apart, de-soldering the negative battery lead first, then positive battery lead and then the 510 lead.  Removed the board, cleaned up the pads and installed a new screen.  I put it back together in the reverse order, 510 lead, positive lead, negative lead.  Pressed the fire button, once, and the screen lit right up.  Reassembled the case.

Unfortunately when I went to unlock it it wouldn't unlock.  All I got was five orange dots on the bottom of the screen.  Now what?  I posted the problem on another forum and BillW50 suggested disconnecting the battery for a half hour.  I also opened a ticket with Evolv and got an response the same day.  Evolv asked about shorts from soldering, but there were none, so I de-soldered the negative lead again and let it sit overnight to be sure.  The objective being to clear any memory that might be maintained by a small capacitor.  The next morning I soldered the negative lead back on and immediately tested for unlock functionality.

Success!  My DNA100C was working again!

 

Two take aways -

1 - Black blobs on the screen can happen from random impact and are not necessarily liquid or screen problem related..

2 - Leaving the board unpowered will clear any memory, corrupted or otherwise.

 

Hope this helps someone else cure a problem like this.

 

[Anyone USB charge their triple 18650 DNA250c?]

I have two 250Cs mounted in N1 cases with 4S/2200mah batteries and have been charging them with USB from day one.  Day one was June 6, 2018 when the 250C was only out for about a month. Excellent battery life by the way, say ~30ML of liquid running at ~30 watts/400F.