lowrance 332C plotter

[3663Ian]

Has anyone come across a problem like this.....
When powered on from the main distribution panel switch, the unit starts on its own and then goes into a constant cycle of bleeping and backlight on off. The chart is being displayed overlaid by the usual "not to be used for navigation" message. Pressing the power button stops it bleeping for a few seconds while it restarts then the cycling starts again. In this state the unit cannot be turned off as it will always restart on its own when the main power is on.

I have disconnected the antenna and the behaviour is unchanged other than the additional lost signal message which appears on the display.

I am certain that the power connections are OK. I have done both hard and soft resets.

This problem has occurred previously and I resolved it by wiping to contacts on the map SD card and reseating the card. ( of course it is possible that this was just coincidental). I have now tried my old chart card and this behaves the same.

The problem appears all the time at the moment.

As the problem has been intermittent I suppose that it is not something completely terminal so any advise or experience with fixing these units would be much appreciated.

Ian

 

[pvb]

Is there adequate voltage reaching the plotter?

 

[3663Ian]

Yes, I am fairly sure the power is ok. At least up to the in-line fuses in the cable tail from the connector on the back of the unit. Obviously it's hard to test the supply under load any closer to the unit unless I open it up to probe inside.

 

[alan_d]

Sounds like a poor contact somewhere: voltage initially high enough to initiate the startup process but as soon as the unit starts drawing current it drops to the level which triggers automatic shutdown, but before this is completed the voltage rises again, aborting the shutdown and initiating startup, but as soon as the unit starts drawing current it drops to the level which triggers automatic shutdown etc. etc etc.

 

[3663Ian]

Sounds like a poor contact somewhere: voltage initially high enough to initiate the startup process but as soon as the unit starts drawing current it drops to the level which triggers automatic shutdown, but before this is completed the voltage rises again, aborting the shutdown and initiating startup, but as soon as the unit starts drawing current it drops to the level which triggers automatic shutdown etc. etc etc.

Yes I agree it does sound like that, so as I said above I have tested the power supply on load right up to the inline fuses in the supply cable. I can't do much more without opening the unit up and it is mounted in the cockpit through the main cabin bulkhead so I have to remove it before I can open it up.

I am still bemused by the fact that I have apparently cured the problem before (more than once and for months at a time) by cleaning the SD card,

Searching on other forums I have found several cases of exactly the same symptoms so it must be a common problem......but sadly no solution.

 

[pvb]

Yes, I am fairly sure the power is ok. At least up to the in-line fuses in the cable tail from the connector on the back of the unit. Obviously it's hard to test the supply under load any closer to the unit unless I open it up to probe inside.

Have you measured the voltage there during the power-up process?

 

[3663Ian]

Have you measured the voltage there during the power-up process?

Yes it was about 12.6 volts, with the engine off and mains charger off. A bit higher ( 13/14V sorry I can't remember exactly what, with the engine running). Both are within a 100mv of the battery terminal voltage.

The voltages are quite stable while the unit is cycling. Though my meter will be averaging the voltage so I wouldn't see any really fast transient.

There is no difference in the behaviour at off charge and on charge battery voltages.

I don't think its high resistance in the circuit to this point. Though I agree with the logic of your line of thinking.

A few things that points away from intermittent power connection are.....

That the unit switches itself on as soon as the power is tuned on at the switch panel breaker. This is not normal behaviour, normally the power button has to be pressed on the unit first. That means that this fault is initiated before the LCD display and backlight are switched on (presumably these are the highest power draw).

Also the cycle can be broken by pressing the power button which causes it to restart and then the cycling does not start as soon as the screen comes on.

The cycling is very fast (say 2/4 times a second) its not a full power up cycle and the maps can be seen displayed in the background under the not to be used for navigation message that can't be cleared. To some extent the unit is running though this cycling. I think even the SOG it being displayed but I would need to recheck that as most of my investigation has been with the boat stationary.

Removing the antenna connection makes no difference except that the signal lost message is displayed, which again suggest that the unit is operating though this.

 

[prv]

If you do give up with DIY and want to pay someone to look at it, I've been happy with http://theservicecentre.eu/ . They suggested by email the likely cause of an intermittent display fault on my Raymarine plotter, and replaced the relevant circuit board plus, at my request, some parts of the case that were badly scratched.

They do have a relatively inflexible process, you must send them the unit and pay for the first hour's labour (£45) before they will do much more than exchange an email or two. But after that point there's quite a speedy turnaround and they do seem to know what they're doing.

Pete

 

[3663Ian]

If you do give up with DIY and want to pay someone to look at it, I've been happy with http://theservicecentre.eu/ . They suggested by email the likely cause of an intermittent display fault on my Raymarine plotter, and replaced the relevant circuit board plus, at my request, some parts of the case that were badly scratched.

They do have a relatively inflexible process, you must send them the unit and pay for the first hour's labour (£45) before they will do much more than exchange an email or two. But after that point there's quite a speedy turnaround and they do seem to know what they're doing.

Pete

Thanks for that I may give them a try if there are no other ideas. Though as the unit is fairly old maybe its time for replacement if I can't fix it myself.

 

[ex-Gladys]

It may sound stupid, the power button on the unit isn't "stuck on" is it? Sounds like one of those keyboard type problems in IT when you pick the KB up and look across the line of it to see a depressed key?

 

[3663Ian]

It may sound stupid, the power button on the unit isn't "stuck on" is it? Sounds like one of those keyboard type problems in IT when you pick the KB up and look across the line of it to see a depressed key?

I don't think its the power key as that still responds, but I will check the others more carefully.