Internal GPS stops working then starts

[flowmotion]

I am experiencing occasional failure of my internal GPS in the TZT2. The unit is about 9 months old. I am using the internal antenna.

Today after about an hour of running off shore the GPS started acting very strangely. It showed the boat moving faster than the drift speed and sometimes shifting direction while drifting (by 180 deg!). Then I began losing position and recovering it. A few minutes after that the position never came back. Sky view showed no satellites. I tried complete powerdowns (battery switch off) to no avail. Several hours later, when almost back at port, the GPS magically started working again.

I don't believe it is a loose wire. I suspected low voltage but running the generator was of no help.

The only cause I can think of is overheating of the unit. It flush mounted in an enclosed partition. Also in there are the DFF1-UHD and DFF3D modules. The outside temperature on that day was 92 F.

This doesn't happen on all trips. I run the same equipment every time.

Any suggestions?

 

[seaveepete]

Overheating would be my guess too if you've taken other possible issues out of the equation. I have two TZT2 12" units and they do get hot. I also have a pair of computer fans pointed at the back of each one which seems to help a little. The screens get very hot too - especially if exposed to the sun. If there is any way you can cool that compartment or at least move some air it might help with overheating and probably increase longevity of the equipment as well.
Good luck.

 

[flowmotion]

This weekend I did some further tests. I used a heat gun to get the ambient over 160F (the spec is 131F). There was no failure of any kind. I let the unit run all day. No issues.

 

[seaveepete]

Did you happen to have another GPS receiver on the boat to verify it was just your TZT2 having issues? A VHF with internal GPS or even your mobile phone to see if Google Maps was working, etc. GPS interference is pretty unusual... the gov keeps that frequency band well protected. Aside from space weather events (CME's, etc.) or intentional jamming (illegal) it would be hard to believe it was interference.
Wait... were you boating in the Bermuda Triangle?? :wink7

 

[flowmotion]

Yes...I have the yamaha helm master system. Guess what, it was not getting a gps signal either. I am having a hard time connecting the two without resorting to little green men. The helm master has its own gps antenna. The TZT2 uses its internal gps antenna.

It is very strange. I tried to find anything on the internet about gps satellite issues now or in the past. There was almost nothing.

Unfortunately I didn't have a gps app on my cell phone at the time. I do now.

 

[flowmotion]

Any input from the Furuno crew?

 

[Johnny Electron]

I could only guess that you are getting some interference by something on or nearby the boat. This could be wi-fi, cell phone boosters or anything that could be near the GPS band. If you doubt the unit, you can always send it in for testing but based on your heat test, it doesn't sound like the unit.

 

[flowmotion]

Johnny,
50mi off shore and no boats around...

I bought a separate gps antenna to hook to PC running TZ Professional. The next time it happens I will try the independent unit.