around the flame box area you will see these-
there is a tiny reset button in the center. Press the button to see if it clicks.
Warning though...quite often a popped reset is sign of a bad exchanger and should be looked at by a professional
Do you have a model number? If it is a "roll out" it will have a button.
If it is a blower or limit switch it will not. The blower or limit will be on the front wall....the rollouts are specifically at the sides or top of the flame area
see page 21-
I don't under stand what else you need I clicked on the link and didn't know what I was looking for!
The location of all the rollouts to make sure you located them.
page 21 has the locations of them.
I see heat exchanger crack = tripped rollout.
I wish you luck and hope all goes well.