I need a public-domain picture that says "Trouble-shooting"

I’m putting together some documentation that has a Troubleshooting section. Can someone suggest a picture that you think would look good as the intro to the section? I’m not paying for it so it needs to be public domain. I’m thinking something like this (but maybe bigger): https://pingler.com/blog/wp-content/uploads/2012/02/troubleshooting-300x225.jpg

Thanks!

Here are some resources for copyright-free images:

http://morguefile.com/

Good luck.

Thanks Shayna! I think I got what I wanted.

There are copyrighted images out there that are free to use, you know. Creative Commons (CC) is one source. What’s important is not so much whether it’s copyrighted, but, for copyrighted items, whether the license terms are agreeable (commercial reuse at no cost, in my case). So public-domain and Creative Commons items would both be acceptable, as well as items whose copyright owner has specifically granted permission.

This has been a Professional Writer Nitpick[sup]TM[/sup]. Thank you.