My carrier thermostat ,stopped working and i have no screen.what does this mean

possible stat failure

Some thermostats run on their own batteries, but some need power from the furnace to display, check this first. "P" may mean power.

The t-stat needs a common and a hot. I know that is simple but it doesn't hurt to ask. Do you have the 24 volts needed to operate the t-stat? If you have 18 volts that may affect the lights.

check fuse protecting low voltage transformer.

you may need to replace the thermostat or the thermostat batteries if applicable. To replace the thermostat follow the instructions on the new thermostat. Make sure to set the thermostat to the gas setting(see instructions) this should cure your problem. Good Luck on the repairs

Dave

the e2 error on your thermostat is a problem with the return temp sensor on your system, the only thing you can really do is call a company and replace it, you can't bypass it or remove it cause the system wont run properly

blown fuse on circuit board, or transformer dead, or hot (red) wire disconnected or broken somewhere in circuit.

You may have a durty evaporator coil do to a durty filter, the heat is cuting off by the limit control sensor

by dark do you mean off? if so check your breakers

Yes, the wires for your thermostat are low voltage 24volts, and there is a fuse that protects it, now if the fuse is gone, nothing will work until you separate the wires and put a new fuse, the fuse is inside the ac unit, if you cant find it, that means it doesnt have one. there for need to check voltage at the transformer.