You accidentally shorted some thermostat wiring because you probably did not turn off the power to the furnace when you changed the thermostats.
There is a 3 amp automotive type fuse in most of those cards that is likely blown, the printed circuit board is generally mounted on the furnace or air handler blower, and will have the thermostat wires run to it.
Look that over, and if replacing the fuse does not work, send me photo's of the printed circuit card showing the thermostat connections, and a clear well focused photo of the wiring diagram glued to the inside of blower door....
use the paper clip icon for that, its at the right end of the tool bar above.
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