Samsung wf8750lsw fills with water starts then cuts out?

use the features fuzzy logic, u only need to power on and start on the machine when u hve fill in the tub with cloths and soap. water will fill in according to the load filled.

That could be the lid switch is open or not engaging.
Check the continuity of the lid switch

The drain line is clogged, unplug. Remove the back panel being very careful not to cut yourself or damage the evaporator. Remove the ice not sharp or pointed objects for this, just hot water. Lay towels down and start pouring hot water until you hear it go down the drain.

Not sure if you mean when it is fully off or operating, but if you mean that once it is operating the door won't open, then the following applies...

Once a front loader wash cycle starts, the door on a front loader is physically (electronically) locked until the full cycle ends after spin dry. This is to prevent anyone opening the door and letting all the water out in the middle of the wash cycle, which a lot of people try to do to put in more clothing etc.

Remove the power for sometime, check the inlet and drain hose connections. If there is good pressure on the inlet then the flow seems ok to the drum. If so the water level sensor must be checked to allow water to collect and cut off the inlet before allowing the drain to activate. If so the controller is a suspect as it opens the drain valve.

Possible that the cut off to the Inlet valve has failed which means that the controller unit is a suspect. Also if the inlet valve is staying ON even when the power is cut off , then it is a case of inlet valve failure.

Display shows 4E.

Water Supply Error occurs when water level frequency does not show changes more than 100Hz or water is not supplied up to the preset water level after 10 Minutes or more at the time of initial water supply. The error status can be cleared by turning the POWER switch OFF and back ON.

could b pressure switch tube is blocked or your control board with the pressure switch attached is faulty. empty water from machine, remove pressure switch hose from control board, blow thru tube to remove any blockages, refit tube. turn on cycle, select low water level, push start, after about 30sec"s push start again, that should stop it filling straight away. if the water stops push start again to continue filling. if it doesnt stop filling after restarting the cycle then it is your control module.if the water doesnt stop filling after the 30 sec stop it is the water valves. by the way what country do u live in because $120 seems to b alittle too expensive. please reply 4 more help.