I bought a used Humminbird 998c SI from another TTFer a while back and haven't had the chance to put it on my boat yet. I have a AC/DC converter power supply and power cable I use for my other Humminbird units to be able to update them on the computer etc and was going to check the software on the 998. I just updated an older Matrix unit I had and then plugged the 998 in but it won't power up. The lights on the buttons light up, it goes to the startup screen for about a second then turns off. The power supply is putting out about 14.5-15V and is rated for 2A. After research I was told that a 2A supply would be plenty for Humminbird units. The only other thing I can do is take it to the boat and plug it in to a known good power on the boat and see if it is the power supply. Please tell me something isn't wrong with the finder.

2A at 12V should operate the unit.
I can run a 1A 12V converter with my 1198's using Simulator.

If you have any map or memory cards in the unit, remove them and see if it will start up.

Wayne P just curious if the 14.5-15V is too much for it? Can't imagine it would be as the Matrix powered up and ran fine. I'll check it again here after lunch

No card in slot, still won't power up. I'm going to try it at the boat just in case the power with the supply isn't 100% clean or right.

No it is not too much, it is rated for 10V-20V. With an outboard running charging the battery it would be getting that voltage.

Well, I know that it must be the power supply I have for the house. I finally got out to the boat and used the power supply there for my old HB unit and the 998 fired right up, works just fine.
I guess its too hard to manufacture an AC/DC converting power supply that actually outputs the rated voltage and amperage. Go figure.

I take the battery from my pond boat into the basement in a cardboard box. It'll last all winter with nothing but a depth finder hooked to it. I'd bet a little tractor battery would work just as well.

I learned to use all my HB's that way.