Swingline Shredder won't turn on

The shredder was working OK but squealing loudly. I took off the top part to expopse the rubber rollers and sprayed them with what I thought was canned air to clear debris, but the spray have some moisture in it. After that, even though the machine parts are clean, it won’t turn on. Do these shredders have a safety switch of some kind, that if the machinery is opened, the machine won’t run?

Sue