Dryer shut down after 10-15 min. Would not restart; error code “dr” appears. Replaced door switch, thermal limiter and safety thermostat per Appliance Pro videos. I thought “dr” referred to the door switch, but this did not correct the problem. Appliance Pro online tech stated there is no “dr” error code??? Currently the dryer green lights for normal dry cycle appear as usual; when start button is pushed green lights flash/beep rapidly and “dr” still appears in error code box??? There is no “dr” on the printed “dryer Tech data sheet” taped to inside of dryer. Can anyone offer help?