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Old 25-08-2010, 09:16   #1
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ST7000 Autopilot Problem - Randomly Steers Hard to Port

I am having an intermittant, but serious problem with my ST7000 autopilot.

At very random times, in either standby, auto, or track, the AP will go nuts - wheel goes hard port all the way, and I can't override it, and displays 'MANUAL' on the display! To fix it, I hit 'standby' to regain control of the boat.

I thought the 'manual' setting was to be able to override the steering from auto in an emergency. This setting is 'off' now.

There seems to be no consistancy when it happens.

Not sure if this is an environmental issue, ie stray energy from radar, etc from other boats, land based communications, etc. two times it happened in the Cape Cod Canal, which has a lot of high power stations. Was just a wild guess. But it has happened in open water as well.

The electronics system on board has a NMEA fluxgate compass (not the original), Lowance chartplotter/gps, AIS receiver, tridata instruments, feeding into a Brookhouse multiplexer. Not overly complicated. I also have a SPOT satellite messenger on board. Not sure if that could cause issues.
But it is disconcerning that I lose total control at random times.

Overall it is working great, other than these random emergencies!

Any help would be great
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Old 25-08-2010, 09:19   #2
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I suggest you go to the Raymarine site and ask the questions. From experience they wouldn't answer till you later reply to the automatic email you will get afterwards asking if they are going to (after the 1 day the message says they would reply in).
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Old 25-08-2010, 09:34   #3
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I did submit it to raymarine. Was trying to expand my seach to see if anyone has run into anything like it in the real world. In the past they have been more than helpful.

Since this is, to me anyway, pretty funky and random, I was hoping others with electronics experience might have a solution.
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Old 25-08-2010, 10:38   #4
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phantomracer,
Contacting Raymarine is a good idea.....
But, before you do so, here are a few important points....

Quote:
Originally Posted by phantomracer View Post
I am having an intermittant, but serious problem with my ST7000 autopilot.
1) What autopilot do you have????
The ST-7000 is a "control head", not the autopilot......
What we (and Raymarine) would need to know is what "CorePak" or "course computer" you have, as that's what is the real "guts" of the autopilot....

Also, I have no idea what boat you have, nor how it is steered (cables, hydraulic, etc.), nor what type of autopilot drive you have (linera, rotary, hydraulic, etc.)......
These are all things which need to be known to better troubleshoot your issue...

Nor, do we have any knowledge if this system was working properly at some previous time????
And, if so, what has changed on-board since then????
And, if it never worked properly, when/where/from whom did you purchase the equipment and when/where/whom did the installation????

Without knowing the above, my advice is just a broad shot-in-the-dark.....but, here goes....


Quote:
Originally Posted by phantomracer View Post
At very random times, in either standby, auto, or track, the AP will go nuts - wheel goes hard port all the way, and I can't override it, and displays 'MANUAL' on the display! To fix it, I hit 'standby' to regain control of the boat.
There seems to be no consistancy when it happens.
2) My first thought was an intermittent of the rudder position sensor or its wiring/connection....and/or intermittent of the heading sensor (fluxgate) or its wiring/connections...
BUT, these should NOT cause this problem if the autopilot was in standby!!!
For some reason your pilot is going from "standby", to turning "On" / going into "Auto", and driving the helm hard over......so, while the rudder position sensor would normally be the first thing to suspect, that would not be turning your pilot to "Auto"......so....


3) So, my next/best thought is an intermittent issue within the CorePak itself.....this is going to be a Raymarine question.....
And, this is why it is important to know what autopilot you have, not what control head you have....


4) Or, as you've already thought of, perhaps an external cause????
But, without any pattern to the problem's occurance it is hard to say if this is a viable possibility....
Quote:
Originally Posted by phantomracer View Post
Not sure if this is an environmental issue, ie stray energy from radar, etc from other boats, land based communications, etc. two times it happened in the Cape Cod Canal, which has a lot of high power stations. Was just a wild guess. But it has happened in open water as well.



5) Typical troubleshooting procedures would be to completely isolate the autopilot (CorePak) from all external connections, except for those directly needed for autopilot operation (12vdc power, drive unit, heading sensor, rudder position sensor, and control head), so that would mean NOT having any other NMEA data connected to the pilot, (NOR using a generic NMEA heading sensor, but rather a Raymarine "Smart Heading Sensor".... although this may seem like a non-issue, it would be my advice for troubleshooting....)
So, disconnect the pilot from your NMEA data bus / multiplerer, etc. AND connect a Raymarine Smart Heading Sensor to the CorePak, and then test the pilot in all the areas / conditions where the issue occured previously.....
If you still have the problem, then the fault lies within the CorePak....
If the problem has disappeared, then we can assume that the NMEA data and/or NMEA heading sensor caused the issue.....
Quote:
Originally Posted by phantomracer View Post
The electronics system on board has a NMEA fluxgate compass (not the original), Lowance chartplotter/gps, AIS receiver, tridata instruments, feeding into a Brookhouse multiplexer. Not overly complicated. I also have a SPOT satellite messenger on board. Not sure if that could cause issues.
But it is disconcerning that I lose total control at random times.

I do hope this helps.....

Fair winds...

John
s/v Annie Laurie
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Old 25-08-2010, 12:33   #5
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Thanks. Understand. My question I was wondering if there was a possible known issue that could cause this to happen. So apparently this doesn't happen frequently and is not a known ongoing issue.

I plan on going down to get the software version of the computer to see if it is up to date.

The AP was working fine for years...before i bought it. There were a lot of changes this year (see the list in my opening post), plus I have a SPOT satellite transmitter/messenger, and boat near high power stations.

But it is super strange. The AP is on (standby, auto (using fluxgate) or track (using gps)) and it can happen. It shows 'manual' (which, according to the manual) is a setting so you can override the auto/track mode by the wheel. It should not show up unless in programming mode.

It happens so infrequently, normal t/s methodologies will be hard to prove one thing or another caused it if it doesn't happen. It may have happend on only about half our trips this year, and only 1x in 5-8 hours of sailing

I am thinking the SPOT could be an offending source..as it is about 1-2' from the computer and it might cause unknown issues when it transmits. That sure is the easy fix - move it to the other side ofthe boat!

I was kinds hoping for a reply like "yea that happened to me..it was the xyx that failed and you need to do this to fix it.........." but I don't think that reply will be coming.
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Old 25-08-2010, 12:56   #6
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Quote:
Originally Posted by phantomracer View Post
Thanks. Understand. My question I was wondering if there was a possible known issue that could cause this to happen.
I was kinds hoping for a reply like "yea that happened to me..it was the xyx that failed and you need to do this to fix it.........." but I don't think that reply will be coming
Sorry, but I don't know of any "known issue".....so, please ignore my advice above (and below), as it is not the answer that you want....but if others have similar issues and/or wish to ask for assistance on-line, I would advise providing as much info as possible.....



Quote:
Originally Posted by phantomracer View Post
plus I have a SPOT satellite transmitter/messenger, and boat near high power stations.
I am thinking the SPOT could be an offending source..as it is about 1-2' from the computer and it might cause unknown issues when it transmits. That sure is the easy fix - move it to the other side ofthe boat!
a) The Spot Messanger transponder is an L-Band (1.5/1.6Ghz) low-power satellite burst-data transmitter....and is VERY unlikely to cause interference to an autopilot....(asssuming things were properly installed and wired???)

Although, if for some reason they are on the same DC power bus, same DC breaker, same DC wiring???? it IS possible that the autopilot CorePak is having an intermittent "low-voltage-issue".....

b) Not sure what "high power stations" you're refering to.....but it is unlikely to be the cause.....(again assuming things are installed and wired properly???)

BUT, since we still have no idea what unit you have, nor what boat, etc....
There's not much else I can offer....
Although, I do wish you luck...



Fair winds....

John
s/v Annie Laurie
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Old 25-08-2010, 13:11   #7
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I did try and make a reliable installation as possible (shielded wires, etc), good connections, etc. The boat has new Rolls batteries (262 ah each), and a balmar alternator, I can't imagine low power being an issue.

I think the first step will be to get raymarine to check to see if I have the latest (or at least reliable) version on the computer.

The boat is a 1968 Ohlson 38
It has for electronics:
Lowrance HDS8 chartplotter
Autohelm st7000 and tridata on seatalk bus
Standard horizon GX2100 VHF/AIS receiver
NMEA fluxgate
all above wired through a Brookhouse Multiplexer
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Old 25-08-2010, 13:21   #8
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The only issue I am aware in some devices is a need for a rudder indicator in the mix. Not sure this is pertinent
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Old 25-08-2010, 13:38   #9
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Where is your fluxgate? You could be storing someting that could be getting the fluxgate to give the head wrong information. Things with magnatic properties like tools will create this problem. Also when was the last time you did the on-the-water calibration? and what was the error recorded after calibration? If you get more than 15 you may need to relocate the fluxgate somewhere else.

I took a compas and went around the boat and placed the fluxgated where there was the least amount of magnetic error.
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Old 25-08-2010, 16:38   #10
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Quote:
Originally Posted by velero View Post
Where is your fluxgate? You could be storing someting that could be getting the fluxgate to give the head wrong information. Things with magnatic properties like tools will create this problem. Also when was the last time you did the on-the-water calibration? and what was the error recorded after calibration? If you get more than 15 you may need to relocate the fluxgate somewhere else.

I took a compas and went around the boat and placed the fluxgated where there was the least amount of magnetic error.
The KVM fluxgate compass is in the wooden table in the center of the boat. no metal within several feet of it. I calibrated it last year according to the directions. Short of hanging it from the ceiling in the cabin, it is in the the most remote part of the boat. It is very accurate compared to the regular compass. Far more accurate than the original fluxgate from raymarine.

It hold the course quite well. I just don't know why it comes out of standby (or auto or track) without warning.
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Old 25-08-2010, 18:34   #11
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We also had an intermittent problem with our autohelm. Ours would go into MOTSTALL error. we tried to find a common denominator when / where etc but found none. Sometimes it would work great for a week and other times error 5 times in a day.

The X30 corepack was still under warranty but we could not get a response from Raymarine. Repeated emails and calling did not rectify this situation. This is not a good time at Raymarine since they were bought out. We were lucky and had purchased an extended warranty from the store we bought it from and they exchanged it for us when I was in the US.
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Old 29-08-2010, 20:02   #12
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I moved the handheld vhf and the spot tracker to the port side away from the course computer..also noticed a wire not super well secured on the multiplexer. resecured it.

used the AP for about 16 or so hours this past weekend and it did not go out of control.

I know this means nothing. Haven't heard from raymarine yet..
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Old 29-08-2010, 20:19   #13
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Quote:
I know this means nothing. Haven't heard from raymarine yet..
It won't matter. They won't fix anything only replace things. You can divide and conquer the problem. You can read the voltage on the rudder indicator. It's just a simple voltage and the calibration finds the center spot. Rudder indicators can go bad and are cheap. It's nice to pray for that. Core computers can have problems. If it is a two part unit where the wires connect via a DB-25 connector pair. That can go bad and short out. The boards are wave soldered and often not very well. Re soldering the two ends to the board often fixes them. I have one with the DB25 connector is going bad so it can't be fixed. While some things can be repaired Ray marine won't actually repair anything. They only sell you an exchanged part or a new replacement. There are a lot of alternative core packs you can use based on the control head you have. Rudder indicators are pretty much the same as are flux-gates.

Things to check include proper installation., You would be amazed at the units not properly installed then suddenly act up. You can test the parts of the system and if it can be validated that the rudder indicator is fine then the next is the compass and last the computer. You test the compass by steering between the 90 degree quadrants. The transition between them is how it can get screwed up. Remove the compass but keep it connected and rotate it below as someone reads the numbers. It should be able to transition all 360 degrees smoothly. If it passes then try it on the water and check for a bad compass location. You just can't know if the location for compass installation really was right. You need to prove it even if it used to work. I went down that road on a previous boat where the original owner, and the PO both never figured out the compass was in the wrong location.
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Old 30-08-2010, 09:23   #14
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Thanks

Still no word from them. But I agree. I was hoping they could tell me if this is a known issue and there is a known upgrade/fix.

Not going to replace the computer just for fun.

The main thing is, it is not only that it goes crazy once in a while, that it displays a mode 'manual' which is not a mode. It is a setting you can change. It is not like im in standby and it goes into track or auto.

For now, I make sure I have someone near the panel if we get in close quarters to override it if it happens .

Very strange..But it worked flawlessly this weekend. almost 50 miles and not a hint of trouble
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Old 30-08-2010, 14:35   #15
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We had an ST4000 autopilot on our prior boat--a 1976 Cal 2-29--that we sailed out of Alamito Bay YC in Southern California for many years before heading to Florida. We often made trips to Two Harbors on Catalina, leaving from Angles Gate. Occassionally we'd come within proximity to one of the Navy's ships coming to or leaving the Long Beach Navel Shipyard. If it was a Perry Class, we'd always disconnect "Otto" because it seemed that one of the radars on that class of ship had a decidedly unpleasant effect on Otto's brains--which we first discovered on a down-wind return from Catalina when it was blowing like stink and the helm was suddenly thrown hard a-port, rounding the yacht up to windward and nearly pitching me into the sea. Ray Marine had no explaination for the problem--just that the computer was sometimes sensitive to electonic emissions.

Maybe you're experiencing a similar phenomina, eh? Have you got anything aboard that may be emitting RFI?

FWIW...
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