Navnet3D MFDBB power issue

[TeeBo]

Hi all,
My Navnet3d MFDBB does not start: when I briefly press the power button on the control unit, nothing happens, most of the time. On a few occasions, i saw a brief flash on the indicator light, followed a couple of seconds later by the light coming on for a second or so and the ventilator on the PC box starting,b but then everything stopping immediately.
I read a few topics on this forum about startup issues but most dealt with software issue after powering up.
Many thanks

 

[Johnny Electron]

It almost sounds like the MFDBB is starving for power or your MCU001 keyboard is. I would use a meter and check the input power of the MFDBB right at the front connection as someone tries to turn on the power. If there is a lack of current the input voltage will pull down as soon as someone attempts to turn it on.

 

[TeeBo]

Thanks for your reply
The power cable disappears in a metal box outside the mfdbb case. Inside the case, it seems to go into a subbox, from which two pairs of black/red 12AWG wires exit. One pair uses a connector to connect to the next sub box and the other goes straight to the next sub box.

1. At the power source, on the other end of the power lead, i measure 26V stable.
Where would be the best place to measure the voltage drop on the MFDBB side? Can I take appart the metal box the power lead goes into?

2. Is there a way i can start the mfdbb without the control unit, to divide which unit is the source of the fault?

Thanks again

 

[Johnny Electron]

Can I take apart the metal box the power lead goes into?

Yes and that is the best place to measure in case of power cable loss problem.

Is there a way i can start the mfdbb without the control unit, to divide which unit is the source of the fault?

Yes, you can make an RJ45 cable that plugs into the keyboard port on the MFDBB and have open wires at the other end. You must be careful but you can momentarily touch the wires going to pins 7 & 8. You could also just wire a momentary switch between 7 & 8. The remaining wires should not be connected or touching anything. When the two pins make momentary connection; it is the same as hitting the power button on the MCU001.

 

[TeeBo]

Thanks Johnny,

So i was able to test with a stand-alone RJ45 cable as you described and the issue is with the mfdbb it seems. I tested with all cables disconnected except the control unit cable, the ground case connection and the power cables.

During the tests, I worked this out:

1. I can get the unit to briefly starts (at most 4 secs) if I disconnect the unit from the 24V supply for long enough (say a minute or so).
2. It seems the longer i have the unit disconnected from 24V, the longer the brief start lasts (to a max of 4s)
3. If it briefly started, it won’t briefly start again unless I disconnect from 24V for long enough.
4. I can’t see the voltage drop or anything when the unit shuts itself off. So I don’t think it’s starving amps because of a bad connection.

Hopefully these observations help narrow done where the actual issue may be located.

Many thanks

 

[TeeBo]

Hi,

It may thicken the plot, but another observation:
5. In order to be able to (however briefly) start the mfdbb, it must (obviously) be on the 24V power supply, but not for too long: If i wait a few minutes after connecting it to 24V, it just won’t start. I then need to disconnect it from 24V, wait a few minutes, reconnect it and quickly press the button. That way I can get it to start, for a few seconds at most.

Thanks

 

[Johnny Electron]

It sounds like the power supply inside the MFDBB. The charging of capacitors can explain the need to disconnect to allow discharge. I would recommend sending the unit in for repair evaluation.

 

[TeeBo]

As a related note, with the MFDBB being out of action, I’ve tried to set the secondary MFD8 (only connected to the hub101) as the master. But now i get a message on startup:
“Your systemID (...) is invalid. Your charts will nonetheless be available for the next 29 launches”.

Everything works ok after that (understandably, considering the lack of MFDBB on the network, i only get data from the other nn3d components like the AIS), but the number decreases, so im going to have a problem soon.

I tried the install wizard and it went through ok. Still I get that message.

Anything I should try to fix it?

Thanks

 

[Johnny Electron]

That message is just a notice about your licenced charts. That is not an error. It will resolve once your MFDBB is returned to the boat as your master and the slave is reverted. Licenced charts will continue working for 30 power cycles which is normally enough time for your other unit to be repaired.

 

[TeeBo]

Thanks

Unfortunately i won’t be able to get Furuno to look at my MFDBB any time soon as I’m out in a remote area. Costs, time needed and risks to send the unit are prohibitive for now.

So I need to work with what i have: my secondary mfd8. For chart plotting and more essentially for the DRS radar.

Is there anything I can do to avoid running out of launches? Surely there are cases where the system has 1 mfd8, 1 hub, 1 rds, 1 fa50 like mine?

Thanks again

 

[Johnny Electron]

It isn't a worry unless you are currently using those licence charts.
It isn't normally done, but it is possible to strip the chart licences from the MFDBB and move it to the MFD8. You should work with your local Furuno distributor with the system ID from both units (MFD8 and MFDBB). This isn't normally necessary or done because the master is normally able to be repaired before the system gets 30 power cycles.

 

[TeeBo]

Ok, i guess I’m surely using the licence charts? I’m the second owner of the boat so I’ll have to research the details of the initial set up, but it might be tricky.
How can i get the systemID of the MFDBB if it doesn’t start? Can Furuno look it up based on the serial number ?

Thanks

 

[Johnny Electron]

We can look up by serial numbers for TZT and up, but not NN3D. Do you remember the "Notice" you talked about on your slave? On the on-screen pop-up it will give you the system ID of the unit it is looking for (your MFDBB); that is the number. Write that down before you get 30 power cycles. It is VERY important that you still own the MFDBB that you are planning on stripping the licence from.

 

[TeeBo]

Yes, i have that number and I noticed it is different from the systemID of the mfd12, so i suspected it would be the MFDBB’s. I still own the MFDBB. I’m hopeful to get it fixed at some point so I very much intend to keep it.

 

[tek]

As my MFDBB behaviour is matching your description 100%, I wonder if you found the issue?
My MFDBB died after 5 days of continuous use and perhaps the heat killed a capacitor or two.
If you managed to find any details of the problem or a schematic, I would like to take part of it.
/Thomas

 

[TeeBo]

Hi Thomas,
No, unfortunately i couldn’t find the issue. Because of the remote location, I haven’t had a chance yet to get Furuno to look at it. I checked the RAM, got a local electronics guy to have a look at the power supply board that checked ok, but could still be an issue when integrated in the bigger box. So at the moment I’m left with the secondary mfd18. Furuno helped me transfer the unlock codes so i could use the charts there.
Good luck, and please do give feedback here if you find a solution.
Best,
Thomas

 

[tek]

The problem is now solved. The power supply board (having a foam cushion at the solder side) was the problem.
I tried checking all the capacitors on the board but non of them was out of spec. I then bought a used MFDBB as a spare and swiped the power supply from it.
Good luck with yours.

 

[TeeBo]

Hi Thomas,
Thanks for the feedback, I’m glad you found your solution. Hopefully your second hand power supply board will give you a few more years of usage.
If you don’t mind, I’d like to know what the price of a used MFDBB might be nowadays.

Best,
Thomas

 

[tek]

One boatunit. (1000$). I organised the shipping.