What is wrong when the sink drains fine but the toilet won flush and the bathtub fills?
Hint-2: If the clog is incomplete, that is the tub empties at a visible but steady rate, you can turn on the faucet in the tub (or an affected sink, to reduce tub splatter) just enough to keep the tub’s water level steady. Then turning on another affected appliance to drain, will cause the tub level to rise. If the tub level does not rise, the appliance drain is connection to your sewer tree below the clog.
