I have been called out to a Norfrost commercial chest freezer where the digital temperature display is not working.
It lists a battery in the parts list and I have been told that the display is run by the battery. The customer says the display has never worked therefore I would have thought there is someway of turning it on as I doubt it would be on from manufacture.
Will be similar to Gram commercial temp indicators,new ones come with a batterey fitted and you just pull out a paper lug to start it working.No on off switch,if you can pop it apart you should find it’s a battery similar to many remote key fobs.
BG