do you have some way to actually check for the presence of voltage?
How does your turn on? Are there switches at the doors for the hose connection (hidden switches generally) that automatically turn the vacuum on when you plug in a hose or open the door or some other actions or is there some manual method of having to turn it on?
Did you read the manual? As mentioned--- have any power? Check the filter/bag for fullness? Is the plug-in on a GFCI (as required in a garage)? The intake at the unit should work even if other remote ones don't.
Be safe, Gary
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.