When you cleaned the vent system did you also check that the exterior louvers were opening?

After you replaced the thermal fuse did you have good air flow out the vent?

Check that the blower wheel is clean and that it is properly attached to the motor.

You may want to try the following
Unplug the unit and disconnect it from the vent system.
Now try a run.
If it now dries OK odds are the vent system needs checking/cleaning.
Be sure to check that the louvers on the outside of the house open correctly.

If you do not want any lint in the house.
Take a pair of pantyhose.
Put one leg into the other and then attach this to the dryer's vent.
Leave enough room so the pantyhose can balloon out like a windsock.

Both the above will let you check the temperature and the air flow.

Try running diagnostics to see if something comes up.

You will need a meter to go much further.

Unplug the unit and check the thermistor resistances.

Check the heater relay contacts they should be open. If not then odds are they are welded shut and the unit is running on high all the time without ant temperature regulating.

Check the heating coil.
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 10 to 12 ohms.
Then check from each side of the coil to the case/frame, both should be infinite ohms (open). If not the coil may have sagged or broken and is touching the case. This can cause it to run on high and the thermostats cannot regulate it so the thermal fuse blows.

Here are your parts
Replacement parts for WHIRLPOOL WED6600VW0 29" ELECTRIC DRYER | AppliancePartsPros.com

See the attachment for the tech sheet

I am a assuming that the unit does not make any noise when you try to start a cycle.

Could be the thermal fuse has blown or the belt has broken.

If the fuse is blown be sure to check/clean your vent system as that is the most common cause of it blowing.