Questions Regarding Humminbird 200DX

I currently have a very old huminbird on my boat. I don't know much about it othere than the screen displays 1994 when it comes on. I'm assuming that's the year it was made which makes sense cause my boat is also a 94 model. So regarding the 200DX...I bought the unit only at the thrift store for 5 bucks. I plugged it directly into the base from the other unit. It fit perfect, got power, and said it recognized a transducer. However, it doesn't work in the water. My question is: are these units any good? How old do you figure it is? Is it worth the risk to buy another transducer for $50 in hopes that it works? Thanks.

I'd say the 200 is pushing 10 years old. If you bought it at a thrift shop, maybe the reason it was there is because it's a dud. See if a local fisherman has a compatible set up to try the head unit on before investing in a transducer.