Hi XXXXXX;
Does the unit have an inducer fan? If it does then the pressure sensor may be shot or there is a plug in the line. One thing you dont want to do is blow into the tube or suck on it. These are very sensitive units and doing so will ruin it.
What you want to do is check for a closed circuit for this item at the connections on the board. All units have a schematic They are located on the inside of one of the covers. Usually on the main fan cover. You can track it down using the color coded wires.
If the induction motor is not starting you need to check for a closed limit switch. Again you can track it down using the schematic.
Check these items and let me know if it starts or not and we can continue from there.
Best regards; THS
Jack of all trades Master of a few.
#1 Home Improvement Expert. Over 30 years experience in construction, and home repairs