Hi,
Here’s the [https://www.vinotemp.com/media/docs/TEDS%20SERVICE%20MANUAL.pdf|VT-12TEDS service manual] which whilst it is not exactly the same model may still be of some help.
It describes how to test the temperature control to make sure that it is OK.
The [https://www.vinotemp.com/replacement-parts-for-vt-12tedi|temperature control board] itself is not that cheap to replace but maybe you can find the problem.
Hopefully a start.