I have only one DNA250C mod, resistance on it measures 0.009 ohm. A bit higher than expected but within acceptable range. My Dovpo College DNA60 measures 0.012 ohm Be sure to clean the 510 and shorting plug prior to testing.
Yes I removed the gasket, coils and packing. It wouldn't make any difference though. A 510 to 510 adapter or any old atty no longer wanted will do also.
You can use the solder of your choice btw.
Also it will require a mini torch or a high wattage iron. I used solder and flux for water pipes simply because I had it.
Regarding the DNA25, it is not EScribe capable so it will not connect to a computer. The DNA250C will connect to a computer, Try using a different cable and a recent issue of EScribe.
Once connected to EScribe open Device Monitor tab, firmware version will be in the bottom right corner.
A couple of things come to mind. Is there possibly another window is hiding under the install window that you must give permission to proceed? Maybe try running it as administrator.
Download and install the full package. Uninstalling your current EScribe isn't necessary.
https://downloads.evolvapor.com/SetupEScribe2_SP71_1_INT.exe
The power (amps) isn't getting to the board. Could be weak battery or a bad connection between battery and board (most likely)
Using EScribe's Device Monitor with the boxes checked like in my image test yours to see how much of a voltage drop that you get. In my example it is 3.26 volts. If it were to drop to below 2.75 volts (default setting) it would decrease power accordingly. Hover your mouse over your Device Monitor to show levels. Post it here afterwards.
My guess is that yours will drop below the set cutoff.