You only have one atomizer?
Know how to use a multimeter?
Could be several things. Sometimes the eVic can hang and will not fire properly on a Freshly fully charged battery.
This can usually be detected by holding the Firing button for about 8 seconds, release and quickly press again. If it starts to fire after a few cycles, this is the issue.
Another COMMON issue is the center post of an atomizer being pushed up and not contacting the eVic center pin. Very common issue and happens with regular
batteries also.(Ego, Vision, etc)
Your atomizer coil could also have popped and is now dead.
Didn't give us much information to work with.