Boat electronics dying.

[Macdoug]

I have a sim rad nss8 with sim rad is20 wind instruments, simrad ac42 autopilot, airman dst810 depth, and ray marine ais as well as a b&g triton 2.

Apart from the airmar and triton which are about 6 months old, it is all 9 years old. It was all working perfectly until about six weeks ago when the is20 stopped working. I figured this is just an age thing and was in the stages of deciding what to replace it with. But today the autopilot is intermittently cutting out (as in the nss8 keeps telling me the signal has been lost), and then the triton 2 (which was also telling me the autopilot was cutting out) stopped receiving any data from anything.

I have looked at all the wiring , apart from up the mast, and can’t find anything wrong. I have tried isolating various components but nothing seems to work. Does anyone have an ideas on where to go next? I would like to avoid getting a professional in if I can.

[Macdoug]

Forgot to add that half way through the afternoon the nss8 randomly rebooted which it has never done before.

[lmxr]

Are the devices connected using simnet? If so, I suggest you take a look at the network diagnostics page in the Triton (does it mention any SimNet/CAN/NMEA2000/N2K network collisions?). Furthermore, you could measure the termination impedance (system should be turned off): https://d2ormn18lhax6.cloudfront.net...0627-40994.png

[Lake-Effect]

Originally Posted by Macdoug

Forgot to add that half way through the afternoon the nss8 randomly rebooted which it has never done before.

Check all your DC power connections to the electronics. Something like a weak or corroded splice, dirty fuse contact or connector pin could account for that reboot and other flaky behaviour.

[tkeithlu]

Pure parsimony would say that you are looking at a network, or possibly power supply, problem, as lmxr suggests. The individual components all failing at the same time is too much of a coincidence to calculate. You just experienced the down side of integrated and glass cockpit instrument arrangements, if indeed you are on a network. If the network, or the monitor, goes bad, you can lose everything at once.

[Macdoug]

Yes I am on simnet. I will look at the power supply issue and check termination as suggested this weekend. Thanks.

[kapnd]

Network connections can make you crazy!
Any open (unused) network ports on the backbone need to have a termination plug in them.
Extra ports on the back of components should be covered, preferably packed full of grease too. Salt fog is often the media they must survive in.
The reboot was likely due to a power interruption, check power source and ground.

[Uncle Bob]

Another point to check is if you have those delightful glass tube fuses they can appear to be ok but still be intermittent. Try replacing one on a suspect piece of equipment and if it works discard the bad one even if it appears OK.

[donradcliffe]

Take the network down and rebuild it one by one. Let it work for at least an hour before you add back each component.

[PerfectPirate]

Try what Donradcliffe said. I have read that the NMEA 2000 bus is an evolution of the Canbus system that is used in automobiles. We had an experience with a Ford Windstar which we owned where the instrumentation and controls were progressively failing and shutting down. First the cruise control, then wiper controls, etc. The problem turned out to be one bad relay which was flooding the Canbus with signals, which prevented the other instruments from being able to communicate.

So, try isolating the instruments one at a time to see if some particular instrument or transducer is causing a problem on the NMEA bus.

[Macdoug]

I think I have narrowed it down to some dodgy connections. When I touched the wires at this point the NSS8 switched off and won’t switch on. Will need to purchase some new connectors and waterproof them (not waterproof at moment and in wet area). Thanks for the help.

[Nicholson58]

Originally Posted by Macdoug

Yes I am on simnet. I will look at the power supply issue and check termination as suggested this weekend. Thanks.

For what it’s worth, 97% of our electrical issues turn out to be poor connections, probably corrosion and most of those are crimp connectors. All new and any repairs mean soldering. I use shrink wrap with silicone sealer or 3M 5200 internal to the shrink. Good insulation, waterproof, stress reliever.

[Macdoug]

I sorted the problem yesterday. The connector looked in good condition but on closer inspection all the contacts were corroded. So while the connection was still solid there wasn’t much electricity getting through and the slightest touch was switching bits off. Now seems stable.

I agree with the shrink wrap and silicon sealer. Works well. An unsealed connector in the fender locker getting salt water on it, not so good.