Right, so I have a TECC V-scope

and it worked perfectly for a few months until recently - it just refuses to produce any vapour.
When I changed the atomiser coil I was good for about 6 hours of occasional vaping until the e-cig stopped working. There were no usual signs of an ageing atomiser like dark e-liquid or a changed flavour; I usually get more than enough vapour on 3.3V with a new atomiser, but now I couldn't even get any at 4.8V.
I've tried changing the bottom bit of the tank

as I had a spare, reassembling the entire e-cig to check if there's been any damage/leakage, but everything looks clean.
Can anyone offer some help on the issue?

and it worked perfectly for a few months until recently - it just refuses to produce any vapour.
When I changed the atomiser coil I was good for about 6 hours of occasional vaping until the e-cig stopped working. There were no usual signs of an ageing atomiser like dark e-liquid or a changed flavour; I usually get more than enough vapour on 3.3V with a new atomiser, but now I couldn't even get any at 4.8V.
I've tried changing the bottom bit of the tank

as I had a spare, reassembling the entire e-cig to check if there's been any damage/leakage, but everything looks clean.
Can anyone offer some help on the issue?