Probably the thermal control is no longer working, make sure you have power on the element when heating up.
If there isn't, work backwards towards the mains input side to fault find.
Question edited for clarity.
Two questions made into one.
Duplicate deleted. Refresh page to see your question.
Thumping is normally can by two reasons
1. Worn rear bearing which normally has a nylon sleeve that wears causing vertical movement
2. Worn or collapsed drum slides or rollers at the front of the drum.
There is not normally foam, the sealer is felt and needs lightly oiling.
No model number given, Google Roper parts diagram
https://www.google.com/search?q=Roper+dryer+replace+rear+bearing+and+drum+slides
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Hello HeatherGood to see you again. The outlet on the back of the dryer is 4" and the wall duct has a 4" tail. The ducting flexible hose made to fit on the outside of both. You fix with large hose clamps. It sound like you are trying to put the dryer into the wall duct? That is not the right way. You have to have hose even if it is 10" worth, that has 4" inside diameter for both the dryer and the wall duct. The new magnetic connector make thing very easy.The parts and the videos are in the linkhttps://www.google.com/search?q=DRYER+WALL+DUCT..
This can only be caused by a few things
Belt slipping.
Idler wheel tight and causing the belt to screech.
A very outside change it is the rear drum bearing or motor bearings.
Take the top off, put a length of plastic tub in you hand and follow the sound.
There are several possible causes of a squealing dryer, including unlevel installation, damaged drum bearings, a faulty drive belt, a worn out idler pulley, a damaged roller shaft or a malfunctioning motor. Discovering the cause of your squeaky dryer can help you determine how to resolve the issue.
There is no definitive instructions to so this. Normally, go around to the back and remove screws or press catches to loosen and remove the top. Remove screws at the front kickplate. Pull the door and front forward, remembering that there are wires attached. Replace the latch and rebuild.
https://www.google.com/search?q=Blomberg+Dryer+dv17542+replace+lock+body+assembly
similar to this on a Whirlpool
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They always screech when the belt slips. There are usually only 2 reasons this happens.
The drum slides at the lower front are worn out and creating too much friction.
Or
The rear drum bearing has worn out, and again too much friction.
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