Cetrek 737 faulty

[Murv]

Right, having been thoroughly convinced of the usefulness of this now, I'll have a go at repairing it!
Any thoughts on where to start?

There seems to be two (unrelated?) faults:

1) The heading it displays is wrong, by up to 180 degrees. Faulty fluxgate?

2) Even if I input the heading that it thinks it's on, after a few seconds the pump fires up and jams the rudders over to wither port or starboard, runs for a few more seconds, then stops the pump.
The pump is quite noisy, best way of describing it is similar to a loud water pump with a loud thrubbing noise, But, it's mounted on a wooden panel, maybe that's normal? And, it certainly doesn't have any problem pushing the rudders.

Everything powers up OK, there are no error messages. It certainly seems to think it's doing a good job, except it isn't!

The rudder indicator works, although it does appear to be off by a couple of degrees. The manual refers to re-centering it but doesn't tell you how...
Can the compass be recalibrated? again, the manual is of no help with this.
All other functions appear to work just fine (except, of course, for actually steering the thing) and no functions return a fault code.

The unit is obsolete now, if no ideas, is there anybody anyone could recommend to have a look at it?

 

[Murv]

Just found this place on Google, I'll give them a call and see what they say

http://www.cetrek.com/Marine Electronic Service MAN.htm

 

[Murv]

OK, just an update for the benefit of anyone searching this thread in the future.
Had a pm from a member to contact a retired engineer and I've just spoken to him.

Incredibly helpful chap, but the bottom line with these old systems is that it's well worth tracing all the wiring through and checking the security of the connections.
If all OK, then it's only really fit for the bin.
The older units (701's etc) are analogue and are usually salvageable, but the 737 is digital, totally obsolete and not repairable.

I'm still waiting to hear back form the service centre, and will update the thread in due course if I get anywhere.
A replacement system from Raymarine is IRO £1300 - £4000 depending on the class of pump required to drive the steering ram.

 

[vas]

I agree on the wiring .

I doubt it's a failure, I'd pursue it further, even removing and reseting the sockets on the black box could help... It's just six screws IIRC to remove the cover.
FWIW, I did have this system installed on MiToS for the deliver trip 5yrs ago now, replaced it with a garmin ghp10 so all bits (bar the rudder sensor that seems to work in your case anyway) is off the boat and advertised here.
Which manuals have you got, there are some PDFs around and I have a couple as well if you want me to email you.
The two seemingly unrelated errors could well be fluxgate compass errors, which one do you have? I'd expect a black box error to manifest itself on the display/s, no?

If you're interested (after you check all your wiring!!!) PM with what you want and what you're happy to spend and I may be able to help. Assuming you're not happy to spend a couple of grand on a new system, I could post the black box and compass to you, check what you need and either keep and pay or return
Pumps are noisy (generally) and if not isolated more so. Mine was way back from the cabins and still could hear the slight whinning over the engines at idle.

cheers

V.

 

[Murv]

I agree on the wiring .

I doubt it's a failure, I'd pursue it further, even removing and reseting the sockets on the black box could help... It's just six screws IIRC to remove the cover.
FWIW, I did have this system installed on MiToS for the deliver trip 5yrs ago now, replaced it with a garmin ghp10 so all bits (bar the rudder sensor that seems to work in your case anyway) is off the boat and advertised here.
Which manuals have you got, there are some PDFs around and I have a couple as well if you want me to email you.
The two seemingly unrelated errors could well be fluxgate compass errors, which one do you have? I'd expect a black box error to manifest itself on the display/s, no?

If you're interested (after you check all your wiring!!!) PM with what you want and what you're happy to spend and I may be able to help. Assuming you're not happy to spend a couple of grand on a new system, I could post the black box and compass to you, check what you need and either keep and pay or return
Pumps are noisy (generally) and if not isolated more so. Mine was way back from the cabins and still could hear the slight whinning over the engines at idle.

cheers

V.

Thanks very much Vas I shall have a poke about and will certainly be in touch if it doesn't sort it out, good to know you have some spares!
It may well be a couple of weeks before I get time, the weekend will be tidying the boat up for a big (for me) trip out the following weekend but if I get any spare time I'll definitely make a start on it.
Cheers,
Chris

 

[johnwest]

It might be worth having a chat with " The Service Centre " based in Wareham. Sorry don't have their details to hand.

j

 

[Murv]

Thanks John, I did email them this morning but haven't heard anything yet (details in post#2)

 

[apollo]

Sorry to hear that.
If your drive train still works (easy to test with power lead and reverse polarity) then you could pick up a 2nd hand Raymarine course computer and ST6000+ header unit probably about £400 on ebay.
Definitely still most useful kit as gives you another pair of hands while you check your charts and engines.

 

[Murv]

Sorry to hear that.
If your drive train still works (easy to test with power lead and reverse polarity) then you could pick up a 2nd hand Raymarine course computer and ST6000+ header unit probably about £400 on ebay.
Definitely still most useful kit as gives you another pair of hands while you check your charts and engines.

It was well worth a try and I really appreciate the contact. Had it been an older unit then he would have been able to do something with it.
Thanks for the advice, that gives me another option to look at if the wiring isn't at fault and Vas doesn't have anything suitable. It would probably be a better option anyway to be able to integrate with the current plotter.

Difficult to know where to go with all this really, at some point a previous owner has spent a small fortune on electronics which is still extremely good, useful kit.
But, at nearly 10 Years old, none of it is current.
The ideal solution will be if the cetrek fault is just down to wiring and costs nothing to sort out! At least that will buy me some time before looking at upgrades in the future.

 

[Murv]

OLD THREAD BUMP

Adding this purely for the benefit of anyone else searching on this problem in the future as there's not a great deal on google and this thread keeps coming up in searches!
The pump running the rudders hard over is most likely due to the phasing of the rudders or the pump being wrong. Therefore, the system senses a change of direction is needed and then runs the pump expecting the rudders to move in the appropriate direction. If their phasing is out it will continue to run the pump waiting for it to change (which of course it won't) and the same problem if the pump is running in the wrong phase.
In the later versions, the phasing can be adjusted electronically through the setup, in earlier versions it's a case of switching the wires around.
Also, those dip switches are critical. Mine was at the point where the system would correct one way but not the other. Simply flicking one of the rudder sensor dip switches solved that issue. The keypad not working on the 727 on the flybridge (powering up and displaying but wouldn't respond) was solved by flicking another dip switch.
With the fluxgate compass, you can either rotate the compass assembly within the housing to align it, or adjust it electronically through the setup.

Big thanks to Ian from Scotland in his help through pm, and I can also highly recommend the service centre for repair work.
They're a little expensive, but far cheaper than replacement kit. They can no longer offer any work on the older 617 course computers but can repair 618's. The technical manager is also incredibly knowledgeable, in my case it was worth the repair bill (I had a faulty comms board) for the telephone support and to be able to pick the guys brains for a few minutes.

 

[omega2]

Does the "heading" on the sensor agree with the magnetic compass?

 

[vas]

Does the "heading" on the sensor agree with the magnetic compass?

not trying to be a smartarse, so a genuine Q: does it really matter?
If you use a chartplotter and send a route to the a/p, it looks like it will do it's job even if the sensor is showing 180deg off.
Of course if you just set a course on the a/p display and expect to follow it, you should have them matched...

cheers

V.

PS. well done to the OP. Seems that these CETREK systems are still going strong, managed to find new homes for all the pieces I had. Only one left is the pump!

 

[omega2]

not trying to be a smartarse, so a genuine Q: does it really matter?
If you use a chartplotter and send a route to the a/p, it looks like it will do it's job even if the sensor is showing 180deg off.
Of course if you just set a course on the a/p display and expect to follow it, you should have them matched...

cheers

V.

PS. well done to the OP. Seems that these CETREK systems are still going strong, managed to find new homes for all the pieces I had. Only one left is the pump!

Too much reliance on electronics can get you in deep ----, and would you follow a route through a heavily trafficed area? more to the point would go auto at all??

 

[Mr Googler]

I have recently acquired a box of cetrek stuff. Used most of it and I think it's great stuff. I have 2 course computers (keeping one of course) and a electronic compass for a 930-727 system should you need anything. Also have a rudder indicator but not sure if that's compatible

 

[Murv]

Thanks all, and thanks for the offer Farsco. I should be OK for the moment, I do need to check the voltage output on my rudder indicator, hoping to get that done early next week and get the setup completed. If there are any issues with it I'll certainly be in touch.
Omega, it does show the correct heading now that it's been adjusted.
Vas, the engineer at the service centre does agree with you and is constantly amazed at how this stuff just soldiers on! I wonder how much of today's kit will be serviceable in 30 years time?!

No, it wouldn't matter if the fluxgate was reading out, as long as it's working it will hold a course on the pilot setting. But, too much risk of confusion for me if it doesn't read the correct heading!
Mine looks to be configured to be able to follow a route from the Raymarine MFD but the engineer warned that in that case, the COG degT must match the Cetrek fluxgate to work so it would have to be calibrated to read true rather than magnetic. I've no idea how good the auto deviation compensation is on the Cetrek, or just how close it would need to be, but I'm happy with it just being able to hold a compass bearing for now

 

[omega2]

Ours is an even older set up Robertson, and has a few errors, but it will hold a course if I point it in the right direction and then set it to auto, we do not rely on route following nor do we let it wander off without a man at the helm. We no longer have the rudder position unit connected, as that was feeding bad signals, and the fluxgate was shot. Got a used one off ebay, and we do ok with what we have.

 

[Murv]

That sounds like a very simple, and robust system.
To be honest, I couldn't really see the point of them at all for our cruising, but I did put a post on here some time ago when I was considering ripping it all out to make some room at the helm, but got enough replies convincing me that it was worth trying to get it running.
I would imagine that some bright spark could probably build a fairly simple system using a raspberry pi or similar coupled to an electronic compass and gps.
I guess for long sea crossings then the ability to follow a course would be useful, but just being able to hold a heading must be the biggest benefit by far, especially in a choppy sea when constantly correcting the steering gets a bit tedious.

 

[Montemar]

I have one of the 737 and it seems to work on compass. It can accept a GPS but presumably this would mean a NMEA output from a chartplotter and not just plonking a GPS unit on the input. Has anyone used GPS for guidance?

 

[omega2]

That sounds like a very simple, and robust system.
To be honest, I couldn't really see the point of them at all for our cruising, but I did put a post on here some time ago when I was considering ripping it all out to make some room at the helm, but got enough replies convincing me that it was worth trying to get it running.
I would imagine that some bright spark could probably build a fairly simple system using a raspberry pi or similar coupled to an electronic compass and gps.
I guess for long sea crossings then the ability to follow a course would be useful, but just being able to hold a heading must be the biggest benefit by far, especially in a choppy sea when constantly correcting the steering gets a bit tedious.

+1, work out where you want go, point the boat at it, switch on and let it hold that course, of course "VISUAL" of your target helps, I use the wind farms, and nav buoys, although our ancient systems will accept nmea they were built before plotters were available to us ancient mariners. Plus local knowledge keeps you from running aground. LOL

 

[OffScotland]

Montemar, the likes of the Furuno GP30 family allow you to make up routes and they generate the necessary NMEA sentences that the cetrek can follow. The multi-cable power/data will give the wires to plug into the NAV1 socket . Ian