O.K. I'm a newbie so please go easy on me.

I had efforvescence in my concrete basement walls so I got a foundation specialist in my house this morning doing some epoxy/ urethane injections. He mentioned that my french drains are broken but he didn't take the time to inspect the collector pit in the basement. He just told me that the humidity was a sign that my french drain is finished. He is quoting me $85 per linear foot to excavate around the house, install a membrane and install new french drain piping.

How do I know that it isn't something as simple as it being clogged or something? Would a camera inspection identify what the problem is? I'd like to eliminate all other causes before making any decision to spend several thousands of $$$. What can go wrong with a french drain and what methods of repair are out there??

Thanks for any advice you can offer.