Ive got an old freezer. Problem is it never turns off . nothing wrong with coldness in freezer but everything is over frozen cause its not turning off. would this be thermostat problem? its an old rank arena 200l upright freezer and its been sitting in storage for years. i followed thermostat wire thingo and found the thermostat under the freezer at the back, there was a knob to adjust but it seemed it was already on lowest setting. there nothing electronic about this freezer just old, simple good quality stuff not like the plastic electronic cr*p you get these days . hopefully simple fix but are thermostats generic to buy. its got on it A50 5134