If it's tumbling you can skip checking that thermal fuse, it's in the motor circuit so if it opens the motor doesn't run. It's right there though, inside that bottom cover, on the blower duct.

Do a visual check of your terminals, often the element wiring is corroded and/or broken, also make sure you reconnected everything properly. My guess is either you have an open thermal fuse or a wiring issue. I've never seen a factory FSP element go bad that fast.

Quick check of the components of the element is to use the resistance or continuity function of your meter and put a lead on one side of the thermal cutout (rearmost little part) and the other on the side of the element. Check from both terminals of each component as it is difficult to see which is the incoming side of the thermal cut off. If your element is intact you'll see high but not inf or OL resistance if you are including it in the test. If you are just testing from thermal cutoff to element there shouljd be little to no resistance. You can also test each piece independently, it only takes a few seconds per component.

Essentially you have 2 120v lines passing under the duct and meeting at the element, one goes straight to the element and the other passes through the thermal cut out and the thermostat then goes to the element. You can and should test these with the unit unplugged or breaker off. In theory nothing is energized but....

Good luck, you can get a cheap multimeter ($15 or so) anywhere that will do what you need.

There are only a few reasons that machine would not heat. I'd like to know why you replaced the element? Was the element circuit open? Did you actually see a break in the coil? Often DIYers interpret poor performance or long dry times as a bad element; I've seen or heard this from customers 100's of times so I'd like to know that the element coil was definitely open.

As the why it would not heat at all: open thermal cut off, lack of proper voltage, bad timer are all possibilities. Do you have a multimeter to test with?