Topic: First Time Out & 998c SI Failed

[MTBob]

After using my newly installed 998c SI for the first time during the past two days, after about 4 hours of use, the unit went into a random turn-off, black screen condition.  For the next day & half the unit routinely would start up, work OK for a while and then the screen would go black.  It probably blacked-out more than 50 times during the two day trip.  Repeated pressing of the on/off button, it would randomly restart and run for a while then shut off.  It made the unit essentially useless. 
Here are some facts surrounding this issue;
- the unit is installed on my Lund 1700 Fisherman, with a 115 HP Merc. 
- two batteries 1) for the main engine and auxiliary power supplies and 2) a separate batter to run the electric motor.
- the 998 is connected to the same battery that cranks my Merc 115 HP engine. 
- the battery has been recently charged and it runs all my other electronic / electrical requirements without a problem
- the control head is connected to the fuse block with a 3 amp fuse that is fed by my main battery
- this is the same connection that I had previously used to run my old X71 Lowrance for the past 6 years
- there are no changes from the old power connection that ran the Lowrance
- the software version is 6.610
While on the water, I tried to figure out what was wrong, and thought it may be a power supply issue of some sort.  I did some data gathering & testing and here's what I found:
- when the unit is operating, the 998 screen shows a nominal 11.9 +/- volts, rising to around 14 volts when at full speed.
- the self test screen showed no issues
- I thought there might be a problem at the cable pin connection, perhaps an intermittent power supply.  I disconnected the control head from the cable and checked the voltage with a digital volt meeter at the male pins, while idling and running the engine.  At idle the voltage was about 11.8-9 rising to 13.8 - 14.2 +/- at 20 MPH.   I saw no indeterminacy in power supply at the cable pins.
- while I had the cable disconnected I also very gently moved the cable pins to see if there was a problem with the pin connection to the control head.  Reconnecting the cable had no effect on the problem.

I have read a few other posts of similar situations.  The solutions offered in the other posts seem to point to some kind of power supply issue.  I don't think that's the case here since none of the other electronics on my boat have power issues and the previous sonar I used - Lowrance X71 - performed OK.

So, are there any other thoughts about remedying this problem?  Could this be a software problem?  If so, what's the remedy?
************** UPDATE EDIT **************
I was just reading the following post http://forums.sideimagingsoft.com/index.php?topic=4053.msg24612#msg24612 from someone having a similar problem.  Just a note in reply to some of the comments on this post - I understand the difference between volts and amps and agree that just because I can see adequate voltage at the cable, it doesn't mean that the amperage is adequate. 
But, wait a minute.  This unit is only fused at 3 amps - meaning that it draws less than that, likely 2 amps.  3 amps is nothing in a 12 volt battery system.  If the battery is able to crank my 115 HP Merc and run my marine radio and bilge pumps, it should have sufficient capacity to run a 2-3 amp circuit.  And, why would the unit randomly shut off while running the engine at full speed while the engine's alternator is charging the battery?
So, as described in the referenced post above, I suppose I can run a pair of cables directly to the battery to eliminate any losses at the fuse block.  If so, what size wire is recommended - and should I run both positive and negative connections to the battery?

Thanks in advance for any advice.

[newkid4si]

Bob
  If I were in your situation, the first thing I would try would be to  eliminate as much as possible.
  I'd locate a known good battery. Not the one that your using now in case that's the problem. After putting it in the boat,
  I'd unhook the power leads at the fuse block and hook directly to the battery including a 3A fuse. If this cures the problem,
  then you know the Control Head, Software and  Cable Connector Assembly are OK and need to check out the power source.
  If you still have the problem, you can now focus on one of those three.
  The reason I included the Cable Connector is that one time while putting the cables in there I did not get the power plug
  properly seated and could have ended up with problems similar to yours. Fortunately someone in the boat spotted my error.

          Mike 

[MTBob]

Mike: Thank you for your advice.  After thinking about the situation more, I agree with your approach to isolating the problem.  I'm traveling out of state with the boat right now, but I think I'll take time to run a pair of #12 wires directly between the control head fuse and the main battery and see what the results are.  If I can get that done and find some water close by, I'll report the results back here.
Bob

[newkid4si]

Bob
   When I need to run 12V to some location in the boat, I've had good luck doing this.
   I buy an extension cord (red color) at Walmart. Cut the ends off. Now you have three
   twisted copper wires in a water resistant coating. Don't remember the gauge, but it works.
   I color about an inch of the white lead with a red magic marker to indicate that it's the +.
   Use black for --.
   Chuck (Sonar2000) had a point about the green wire picking up electrical noise.
   So I stripped the ends and wrapped them around the black making a double ground.

            Mike   
   
   

[MTBob]

OK, so I don't waste anyone's time on this issue, let me update you on where I am with this problem.  I began doing a direct wiring connection to the battery and found what may be the problem.  The wing-nut screw connector on the battery terminal was knocked loose and the wires were not secure.  After tightening the screw and running the HB for a while, it seems to work OK... at least on shore.  As soon as I can get to some water I'll give it a run.
So...right now I'm going to chock this issue up to a  "Dumb Ass Operator Problem".

Embarrassingly
Bob

[newkid4si]

Bob
   That will be great if that turns out to be the solution.
   Don't take it personal. These things can,will or have happened to many of us.

            Mike

[Humminbird_Greg]

I hope that was the cause of the problem Bob.  That way you will be good-to-go.

Don’t knock yourself about the loose wing nut.  I mean it’s not like you installed both the positive and negative power leads on the same ground terminal of the battery or anything… 
Not that I have done so, but I have a friend, who’s wife’s second cousin on her aunts side… 

Work on boats long enough and you either get to see someone else’s mistakes or make enough of your own to become “experienced”!