# Lowrance LMS-337c Power Issue



## Bluegill11 (Aug 27, 2016)

Hello Everyone,

I'm in need of assistance from someone familiar with the Lowrance LMS-337c models. When I connect to 12V and hit the power button, the display just quickly flickers once and does not power up at all (no beeps). I've already confirmed that I'm feeding the unit 12V and there is no corrosion or damage to any of the pins. Also there is no fuse link on the wires, so that can't be the issue. 

I've already contacted 3 or 4 repair companies and they said they're unable to service this model. Does anyone have any ideas? I'm comfortable opening the case if necessary.
Thank you in advance.


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## K gonefishin (May 4, 2004)

Power cable should have a fuse. Are you going from lowrance power cable to another cable by chance?


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## Bluegill11 (Aug 27, 2016)

K gonefishin said:


> Power cable should have a fuse. Are you going from lowrance power cable to another cable by chance?


The power cable is connected directly to a 12V battery with no fuse in-line. Perhaps something blew inside?


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## K gonefishin (May 4, 2004)

Bluegill11 said:


> The power cable is connected directly to a 12V battery with no fuse in-line. Perhaps something blew inside?


Should have a inline fuse I’ve owned at least 10 lowrances all used fuses inline they come with them.


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## wave warrior (Oct 2, 2005)

Always need a fuse somewhere in the power line ,


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## Bluegill11 (Aug 27, 2016)

Yes I should have had a fuse connected to begin with. I had the unit powered on without one: It stayed on for a few minutes then it just turned off all the sudden. Now when I press the power button the display just gives a quick flicker of light and nothing else. I'm just searching for a possible way to make a repair on my own since no one works on them anymore.


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## K gonefishin (May 4, 2004)

Bluegill11 said:


> Yes I should have had a fuse connected to begin with. I had the unit powered on without one: It stayed on for a few minutes then it just turned off all the sudden. Now when I press the power button the display just gives a quick flicker of light and nothing else. I'm just searching for a possible way to make a repair on my own since no one works on them anymore.


Did you try putting a fuse on it now? honestly you can buy those units for darn cheap so not the end of the world if you can't get it to work.


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## Bluegill11 (Aug 27, 2016)

K gonefishin said:


> Did you try putting a fuse on it now? honestly you can buy those units for darn cheap so not the end of the world if you can't get it to work.


Yes, I attached one yesterday to see what would happen and it just does the same thing (a quick flicker at the touch of the power button).


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## crappiedude (Mar 12, 2006)

I know some Lowrance units have a hard or a soft restart.
Have you tried a restart?
Who knows if this will work for you or not but it may be worth a try.

On the HDS units a *soft restart* would be
1 Turn off power
2 Press and hold Pages key
3 Press and hold Power key
4 Release both buttons when USA Map appears

Again for HDS units a Hard restart would be
1 Turn off power
2 Press and hold the Z in & Z out keys at the same time
3 Press and hold the Power key
4 Release both when the USA map appears.

My guess is the unit is fried internally somehow.

One of my HDS units did the same thing a few weeks. I just turned it off and 10 minutes later it came back to life. My guess is it will self destruct one day and I'll be shopping for something new.

Good luck and let us know how it turns out.


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## K gonefishin (May 4, 2004)

It’s not an hds unit but they all do have resets. I have a unit if you want to buy it


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## Bluegill11 (Aug 27, 2016)

crappiedude said:


> I know some Lowrance units have a hard or a soft restart.
> Have you tried a restart?
> Who knows if this will work for you or not but it may be worth a try.
> 
> ...


Thanks for the suggestions -- I tried that procedure several times and it just didn't work, so I'm guessing something internal did fry. I'll just end up throwing it up on ebay to sell for parts; transducer and speed sensor too.


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