Eltrim ST Trim Tab Control Repair

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John100156

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I have a faulty Eltrim ST controller (old black box type with green/red led's size 110mm2) on my FB which I have stripped ready for repair, generally one tactile switch needs changing and some minor corrosion on the PCB needs sorting.

I can order a new unit, the part number is: NR.FST12-24V, but given the switches are easily sourced I want to see if I can repair the old unit. Also, the new replacements are slightly smaller and need a trim.

Anyone know how to test these units, I have identified +ve and -ve terminals and can probably work out the rest, but what is the resistance of the feedback potentiometer that is fitted to the trim tab motor? If I know this, I can test if it's working before taking it back to the boat!

Any help much appreciated.
 
Just repaired mine with the advice of several good guys on here.
I never tested the unit prior to fitting but hey presto it worked.

Edit:
If the unit in the lower helm is working you could always stick a meter on that for reference measurements.
(I'm assuming the unit that's not functioning is the fly-bridge one)
 
Last edited:
Thepipdoc said:
Just repaired mine with the advice of several good guys on here.
I never tested the unit prior to fitting but hey presto it worked.

Edit:
If the unit in the lower helm is working you could always stick a meter on that for reference measurements.
(I'm assuming the unit that's not functioning is the fly-bridge one)
Click to expand...

Yes, lower helm and tabs are working fine, only trouble is the boats in the Med and I'm in the UK!

I wanted to affect a repair prior to going out next. I believe the lower helm unit is different. Tell me, when you repaired your unit, were all the red and green led's on when you completed the repair? That is assuming you connected it to 12v?
 
John100156 said:
I have a faulty Eltrim ST controller (old black box type with green/red led's size 110mm2) on my FB which I have stripped ready for repair, generally one tactile switch needs changing and some minor corrosion on the PCB needs sorting.

I can order a new unit, the part number is: NR.FST12-24V, but given the switches are easily sourced I want to see if I can repair the old unit. Also, the new replacements are slightly smaller and need a trim.

Anyone know how to test these units, I have identified +ve and -ve terminals and can probably work out the rest, but what is the resistance of the feedback potentiometer that is fitted to the trim tab motor? If I know this, I can test if it's working before taking it back to the boat!

Any help much appreciated.
Click to expand...

John I have one on eBay at the moment, the boat now has lenco tabs. I'll take it off no bids yet you can try it, I repaired one before they're very fiddly to get apart so well done so far!

Email a mailing address.
 
John100156 said:
Yes, lower helm and tabs are working fine, only trouble is the boats in the Med and I'm in the UK!

I wanted to affect a repair prior to going out next. I believe the lower helm unit is different. Tell me, when you repaired your unit, were all the red and green led's on when you completed the repair? That is assuming you connected it to 12v?
Click to expand...

Ah sorry I didn't realise you were overseas.

I never tested the unit at all prior to fitting so I don't know if the lights were on.
A couple of people that might be able to help is Halcyon or Asteven221.
Also this link might help you.
http://www.ybw.com/forums/showthread.php?t=327249
 
Thepipdoc said:
Ah sorry I didn't realise you were overseas.

I never tested the unit at all prior to fitting so I don't know if the lights were on.
A couple of people that might be able to help is Halcyon or Asteven221.
Also this link might help you.
http://www.ybw.com/forums/showthread.php?t=327249
Click to expand...

Thanks for the link. I had read it before, it's where I found the part numbers for the tactile switches! So it was really useful! With your and Elessar's help, I can repair my unit, check it with his, take both out to the boat and it should sort the problem! What a forum!
 
John100156 said:
Anyone know how to test these units, I have identified +ve and -ve terminals and can probably work out the rest, .
Click to expand...

The five core cable has numbers on each wire,
1) .. trim tab motor
2) .. trim tab motor
3) .. wiper on pot
4) .. positive feed to pot
5) .. negative feed to pot

You can measure the pot resistance between cable 4 and 5

The pos and neg terminal block may have two other terminals for a pressure switch for auto unit.

Brian
 
Thepipdoc said:
Ah sorry I didn't realise you were overseas.

I never tested the unit at all prior to fitting so I don't know if the lights were on.
A couple of people that might be able to help is Halcyon or Asteven221.
Also this link might help you.
http://www.ybw.com/forums/showthread.php?t=327249
Click to expand...

Many thanks Brian that's useful, unfortunately, I can't measure the pot at the moment as the controller is with me in the UK and the boat is in Spain, I was going to simulate, if someone could tell me it's resistance. Then I could check the outputs and LEDs.....
 
John, from memory the head unit has a voltage comparator chip with some resistors in series to get voltage steps to compare against, it then only compares the voltage coming back from the RAM against 0V to +12V and lights the LEDs accordingly.

Thus you can test it with any pot or just a variable 12V supply.

As you have the head at home, if you Google the chip number that should help identify how it works. I traced the circuit on the board and was surprised how simple the unit was.

I guess if you have 0V in then it would be possible that all the LEDs are lit but doesn't sound quite right.
 
John100156 said:
Many thanks Brian that's useful, unfortunately, I can't measure the pot at the moment as the controller is with me in the UK and the boat is in Spain, I was going to simulate, if someone could tell me it's resistance. Then I could check the outputs and LEDs.....
Click to expand...

Should not be critical, the top and bottom end voltages are fixed, so a 1k - 10k pot should be fine, your just varying the voltage between supply and ground.

Brian
 
ANDY59 said:
+1 , the one on my flybridge had a funny 5 mins a while ago but seems ok at the moment . There must be a market out there for someone clever with a soldering iron .
Click to expand...

The amount of work to get one apart normally out weights the profit.
Remember they are German made, so not up to British engineering standards.

Brian
 
halcyon said:
The amount of work to get one apart normally out weights the profit.
Remember they are German made, so not up to British engineering standards.

Brian
Click to expand...

I agree, they are a fiddle to release (de-solder) the PCB from the four tactile switches but many years ago I did quite a lot of electronics work, just for fun, so enjoy the challenge. I had not used my de-soldering suction tool tor manys years and it still works! I do like the idea of tracing-out the circuit and looking up the IC function but my time resources are a bit stretched at the moment.

Any other info/comments gratefully received, I hope to complete the repairs early next week!
 
John100156 said:
but many years ago I did quite a lot of electronics work, just for fun, so enjoy the challenge. I had not used my de-soldering suction tool tor manys years and it still works! I do like the idea of tracing-out the circuit and looking up the IC function
Click to expand...

Watch out, John - things have changed over the years
Not the case for this little project but in my experience circuit designers now tend to use pic chips and simply wire inputs/outputs. Then internal software sorts out the logic. This makes tracing a curcuit a little more difficult and virtually impossible to copy. Often easier to start again.
So be aware when debugging more modern electronics.
 
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