No power to my furnace thermostat?

I have an old Coleman model 184 Forced Air Furnace . I installed a new thermostat and worked for a day but now has no power in to it . I checked all breakers and fuses in the house and they are all alright . No power out of LOAD on the transformer .Can't check the LINE part since there are no probes on it . Old thermostat had only two wires connected and i connected the same way . Did i damaged the transformer accidentally ?! Not sure !!! Any help before going to buy another transformer . All parts on furnace are original and old .Plz help