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Replacement parts for GE GSD3620F00BB | AppliancePartsPros.com

So something else keeps the solenoid holds the draining valve open.
The way it works is that the solenoid is activated for about 10 seconds at the start of a drain cycle. The flapper valve moves to the drain position. The water pressure holds the flapper valve close until the unit is empty.
If the solenoid is activated by the timer for longer that 10 seconds it will overheat and be damaged, you have already replaced it and had no solenoid overheating so It will be OK.
Usually you can hear the pump begin to growl when the unit is empty.

Probably the unit has a drain problem so the flapper always has water pressure on it and stays in the drain position.
I would operate the flapper manually just to be sure it is not sticking.

Next I would investigate a drain problem.

Remove the sump cover (inside center of the tub) and check for debris or something wrapped around the chopper.
Be careful as often there is glass in the sump. Also note how the inside piece is installed, reinstall it incorrectly and the chopper will eat it.

Check the drain hose and house plumbing for plugs. Especially where the drain hose attaches to the house plumbing.

Check the Piston and Nut (Item 564 Section 1). This is under the back cover inside the tub at the rear. It unscrews.
This is a high probability as they often cause problems.

Part number: AP2616850