I'm trying to test a used fish finder in my swimming pool just to make sure everything is okay.  It's a Lowrance X65 in pretty good shape, but I think the transducer lead may have a short in it.

I hook everything up and it starts scanning fine with the 6ft. depth of my pool, then I move like 1/8" and it goes haywire and all of a sudden, we're in 28 feet of water with tons of bottom structure and fish everywhere, I move again, and we're back to the featureless 6ft. flat bottom of my pool.  I messed with sens. settings and stuff for about an hour and that's my only conclusion.  The transducer may be sufferring also because it was a thru-hull mount with epoxy and it didn't come off real clean, so the guy took it to his wire wheel on his bench grinder.  I think he may have went a little too far and got past the casing a bit.  Does anyone have any idea's on whether or not my diagnosis is making any sense?  I'm pretty confident that I have a bad transducer.  I just can't see spending $50 on a new one for a unit this old.  Maybe put a wanted thread on here for a good used transducer?  We're on a low, low budget here.  Spent all my money on the boat, don't have much left to buy accessories!

I went to a local marine dealer and went to the back and talked with the mechanics. They had a large box of spare transducers left over from new instalations on new boats. They told me to help myself two a couple of spares. you may try this. I would avoid the front office though....................Al

Forgot to mention mine was an x85.............Al

Yep, sounds like a bad X-ducer.  Al's got a good idea about calling the local marine dealers. You can also find them on Ebay, used for pretty cheap.  

Here's a couple sellers on ebay that sell used parts they've stripped off junked bass boats

http://stores.ebay.com/TRACKER-MARINE-GROUP_ELECTRONICS_W0QQcolZ4QQdirZ1QQfsubZ7QQftidZ2QQtZkm

and

http://stores.ebay.com/OZARK-BOAT-PARTS_W0QQssPageNameZstrkQ3amefsQ3amesstQQtZkm

I've bought stuff from both these guys and have been very happy with quality and price.

Speaking for the X65 > If for any reason the connection to the transducer is disconnected via (nicked,short,crushed,bent or not seated properlyin the bus)> The depthfinder will automaticly goto the TUTOR mode and all your seeing is the recored display used to train you on learning the features. I've had this happen a few times while underway and I really thought the lake was that dam good till I could see bottom as the depthfinder read 33 ft..  Don't buy a used on without a warranty or unless its given to you free.  Also you need a min . of 3 ft. depth of water for the X65 to operate correctly.  So check your connections! cause you can't repair a transducer.

Good info. from all of you.  Thanks for taking the time out to help me.  I think I might try that local marine dealer first for used ones, and if they have none, then try ebay and such.  Also good info on the tutor mode.  I had never thought of that.  That may be what it's showing me, but the connection is good and tight.  I think I just need to try another transducer and see if that solves my problems.