Hi, my name is XXXXX. X am eager to help you solve your appliance problems.
The plastic fitting that the fill hose attaches to is the mixer valve. If the hot works but not cold then the valve is probably bad. You can check power to the valve to confirm it is bad.
You may send additional questions directly to me.
If I have answered your question satisfactorily - please press the "ACCEPT" button, as this is the only way we receive pay for our knowledge and time. Bonuses are GREATLY appreciated as well as feedback.