Depth finder does not work-

[riverrat56]

I was getting the boat ready yesterday, got the depth finder put back in, and it won't turn on.

It's a cheapy, an Eagle Fish Mark 320, I checked voltage at the plug and there is 12.8v getting to the depth finder. It worked last fall and was stored inside all winter, now it does nothing at all.

Thoughts?

Thanks guys.

[LMITOUT]

Corrosion on the connector pins maybe? Try seating and unseating the connector a few times and try wiggling the connector too. Might be a long shot but worth a try and cheap.

[PerchJerker]

LMITOUT's idea is a good one to try. Another possibility is working the power button on the 320 in case it's sticking inside the casing.

[soldoncass]

I've had that problem in the past, and I'll tell you what mine was.....I sanded the contacts on the plug, sanded the fuse ends AND the contacts on both ends...still didn't work. Then I took the fuse out, and stretched the spring out a little...walah, that did it. Every contact is suspect....after double-checking all those and the fuse, it could be the switch. The finders I have will not work if the voltage is down too low (10.5 V mostly). Every dirty contact can drop the voltage a little more.

[PerchJerker]

soldoncass - those are some excellent points that you made, but in this case he tested the voltage at the plug and is getting 12.8 so that should rule out anything having to do with getting power to the unit.

[Capt. Don*]

How did you measure voltage at the connector end, and what did you use? 12.8 volts on the power wire, what about the ground side, try using a test light across the power and ground terminals on the connector. If it will light a test light brightly then you have checked the power and ground circuit and ruled out voltage drop as well. A dvom will measure voltage, but doesn't put a load on the circuit as a light does. If the light glows dimmly, you have a voltage drop, or high resistance, at a connection or in a wire. If the light is bright that circuit is alright and its on the depthfinder side of the connection.

[GBPackerNut]

Capt Don has a good point, most multimeters have a 1MegaOhm resistance across the voltage side terminals.

The other would be to make sure the pins are both present in the back of the finder case, I had one get damaged before, I dont know how but something bent the pin over.

[riverrat56]

Thanks for the help guys, I know there is no problem at all with the voltage getting to the plug, I even bypassed the fuse and fuse holder just to check if that was the problem.

Not really sure if I want to tear into the depthfinder itself yet, but it does sound as if the power switch could be bad?

[Hookey]

I have the 320 on my boat and you do have to hold it in for about 3 seconds before those units will turn on. I am sure you know this but I just thought I would mention it.

[Capt. Don*]

You've mentioned the power side of the circuit, be certain to check the ground side of the plug if you haven't already. You can have all the power in the world at the plug but without ground its a no go.

[Pat K]

With an Eagles 502C I've had problems with the copper sleeves inside the female end of the plug peeling away from one side of the plug. The pin on the depth finder doesn't make good contact and the unit won't power up. When I'd check it with a tester light it would light up because the pointed end on the probe would go in deeper and make contact.

I used a dental pick to carefully bend the sleeve back into the right position and it worked for about a year. It's conected to a Minnkota with US so I got a new link when it happened a second time. Now I'm carefull when I plug it in to make sure everything lines up just right.

[danfall]

Polarity okay?