Issue with DNA 30 mod

[Sally_]

I'm having an issue with my dna 30 box mod (DZ D30L) the display isn't showing resistance, just 0.0. It's still firing, seems to be working fine as far as voltage being correct for the resistance and wattage setting, but I'm hesitant to use it. I use carto tanks mostly, but I was using an rba when I noticed the problem. I don't know what to do, is there anything that can be done?