Old depth sounder repair

[Mikiebee]

I just acquired an old Hummingbird Tom Mann Birdtrap portable depth sounder. Unfortunately I can not get it to power up. I have checked the power cord and there is power to the unit. Also there is a rattle inside the unit indicating that there are parts loose. It is not worth paying to have someone repair it (if it is even repairable) but I don't want to just throw it out. I can not see any good way to open the unit to see what is going on inside. Does anyone have any idea of how to open this flasher unit without tearing it up.

 

[studlymandingo]

Re: Old depth sounder repair

That is probably a nitrogen filled unit. If it isn't working now, won't hurt anything to yank it open and see what's inside. If you do get it working, put some kind of dessicant inside to dry it out before it is reassembled. Then I'd use a good sealant around the housing and all of the screws. Good Luck

 

[Mikiebee]

Re: Old depth sounder repair

Thanks for the reply. Since I did not get any response for a while (not even from the Hummingbird repair shop in Eufaula, AL) I decided to have my way with it. It turns out that the small plastic panel on the back where the power and transducer connections are just clips into the main housing. I worked a knife blade in the joint and gently pryed the panel out. From there the guts of the unit just push out from the back. Once inside I found that the motor mounting screws had somehow come loose which had disconnected a small brush that apparently grounded the motor (the screws and small brush were what was rattling). Once everything was put back in place and the housing and connections were reassembled, it fired right up. Other than the circuitry there is not really much to those old depth finders. Very simple mechanically. Just thought I would recount in case anyone else had the same problem.