Minn Kota 3hp...anyone have one?

[sam am I]

Perhaps this might help as well...assume brushes, commutator and armature are good to go?

 

[sam am I]

More lame attempts at paintbrush drawings/editing but, the gist is in there....

F = Forward, R = Reverse

 

[gm280]

Sam the schematic diagram I was referring to was for the actual circuit board. But anything is a help at this stage. Again, so hard to trouble-shoot via comments.

 

[sam am I]

Sam the schematic diagram I was referring to was for the actual circuit board. But anything is a help at this stage. Again, so hard to trouble-shoot via comments.

I know, didn't want to get too bogged down in too gross of details for jeep at this point. Thinking if jeep can get'r hooked up right, we'll be able to hopefully beat this thing into submission without too much board/component level stuff.

Thinking It could be simple hook up at this point, just need jeep's few basics board measurements to know which direction to go....Top level (post #42 with #40, #41 hook ups) is my hopes still w/o too much drilling down (crossing fingers)

jeep, where ya at on that ground measurement? Pin #5 of UA3842 has to be common with the batt. negative post or we have issues!! See post #42

 

[jeepwm69]

Great news! Brenda at Minn Kota found me a diagram for the switch. I'll get things hooked back up this weekend and hopefully will have this one ready to be used again!

The attachment had the wiring schematic at the bottom. That's how I hooked up the switch.

If I take the leads going to the foot/ armature, and connect to 12V, the prop spins, so that puts the issue somewhere up top.

Sorry been busy this week, so haven't had a chance to get back out to the shop to measure on pin 5. Gotta take the wife out tonight but will try to check it tomorrow.

View attachment 3HP SS TM.pdf

 

[jeepwm69]

Great news! Brenda at Minn Kota found me a diagram for the switch. I'll get things hooked back up this weekend and hopefully will have this one ready to be used again!

I will say I'm not 100% sure that the switch is good. That's why I started with taking measurements there.

 

[sam am I]

I will say I'm not 100% sure that the switch is good. That's why I started with taking measurements there.

Okay jeep, let us know what ya find when ya get time (some of us have more than others )

Oh and the drawing's and edits to documents I've posted above are solely my interpretations based on the observances of the design and how it was done by the manu. They're not official documents and could be incorrect but, are done to my best belief of what I've seen in the photo's etc., just say'n..........

Enjoy your night out man!!

 

[jeepwm69]

Haven't forgotten about this, just had a really hectic few days.

I'll try to get back into it over the weekend and report back.

Thank yall for the help. I appreciate both of you taking the time to weigh in.

 

[sam am I]

Haven't forgotten about this, just had a really hectic few days.

I'll try to get back into it over the weekend and report back.

Thank yall for the help. I appreciate both of you taking the time to weigh in.

NP Jeep. I noticed an error I had above so I added an edit to #42, the power for the UA3842 is on the N.O. side of the relay's as shown below. From a trouble shooing standpoint, it is significant enough to drop a heads up.

This means that the relay's have to energizer in order for pin #7 of UA3842 PWM chip to be powered up.

It appears that there is transistor next to the relays that drives their coils (see "+12V On/Off"). Not clear what drives that transistor, BUT guessing here again so take it with a grain....It looks like rotating the speed control handle tells the transistor to energize the relays via what looks like perhaps one of the Op Amp's channels configured as a voltage comparator.

 

[gm280]

Not sure how it all is connected because I figured once all the burnt parts were replaced, it would be fixed. If I would have traced al the runs and had all the needed parts to assembly it to one of my TM's, I could have headed off any more problems. But as the saying goes, that is now water under the bridge. Obviously the twist switch isn't handling any real amount of current and there for all the other parts are doing that. So again, I would love to see a real schematic diagram for this circuit board. JMHO

 

[sam am I]

Not sure how it all is connected because I figured once all the burnt parts were replaced, it would be fixed. If I would have traced al the runs and had all the needed parts to assembly it to one of my TM's, I could have headed off any more problems. But as the saying goes, that is now water under the bridge.

Don't sweat the small stuff gm, this is a great learning tool. I'm glad you didn't!!

Obviously the twist switch isn't handling any real amount of current and there for all the other parts are doing that. So again, I would love to see a real schematic diagram for this circuit board. JMHO

The encoder/pot on the flex ribbon cable isn't, agreed BUT, the main switches internal to the housing when the handle is twisted, are, right?

 

[gm280]

Don't sweat the small stuff gm, this is a great learning tool. I'm glad you didn't!!




The encoder/pot on the flex ribbon cable isn't, agreed BUT, the main switches internal to the housing when the handle is twisted, are, right?

If the switch is connected via the flexible PC film, It isn't handling any amount of current, it literally can't. I would melt that flex board instantly. So everything from the switch set up has to be controlling the real current handling parts on the PC board. JMHO

 

[sam am I]

If the switch is connected via the flexible PC film, It isn't handling any amount of current, it literally can't. I would melt that flex board instantly. So everything from the switch set up has to be controlling the real current handling parts on the PC board. JMHO

I think we're saying the same gm.........There are obviously high current contacts inside the switch housing BUT, on the outside, there is a pot/encoder on the end of the flex cable that sends low current signal that feeds, via a opamp channel, the UA3842 and dictates the pulse width BUT, also and again, I'm only guessing but, IN order to energize the relay's, It appears when the low current signal (speed control signal) is present, it is used to flop a comparator's output which in-turns drives the transistor that drive the relay coils.

 

[jeepwm69]

Well I tried to check this thing over again this weekend, only to discover that my multimeter had taken a bath, so I'm waiting on a new multimeter. Hopefully will get a chance to mess with it again in a day or two.

 

[sam am I]

Jeep,

Ya might, if you haven't already, have to make sure the handle/throttle assembly is back together all the way to get it to fire up.

I picked up a board like yours just out of curiosity and as such..........

I haven't drawn/scoped it out too much yet, just got it but, it looks like the handle/throttle assembly must have a button of sorts on the back side some wheres that,...........when the handle/throttle is assembled and in proper place, the button on the back side of the throttle presses in on and rotates about the face (layer 1, see picture A) of this two layer flex cable embedded potentiometer (pot) area.

As the throttle is rotated, the button is at the same time sliding on the flex cable layer 1 and pressing it into the pot's carbon area layer 2 (see black/dark areas [Fwd and Rev] picture B) creating a varying resistance. This then develops a varying voltage sensed by the on-board circuity (comparator) and appears to be used to turn on the relay's. It is also is used to vary the PWM of course..

Mine has a crack (might check yours too! could be a issue for you as well) in a flex trace i'll have to fix but, once I repair it, I'll fire it up and grab some wave forms/reading and post then along with a drawing of the board.......BTW, we can bypass that main switch and eliminate it as a possible issue if need be......Lets first get the board powered up, my gut says the switch is fine.

Pic APic B

 

[jeepwm69]

The "ground foil" is actually the ground traces remaining on any circuit board. And lots of time they manufacture circuit boards with a lot of ground material remaining on the board to help with noise rejection and save on acid material used to remove it. So the majority of the metal material remaining on this circuit board is a ground. So take a meter set to resistance and verify you have continuity between the top side and bottom side of the ground material.

So test this area with an area like it on the bottom to verify they read zero resistance....or very very close to zero. Test it with this bottom side

Post your results.

Got my new multimeter yesterday. Checked the bottom of the board with neg probe, while + probe was on battery +. Got full voltage reading so the "ground foil" does appear to be grounded.

Still nothing when I check pins 5 and 7.

I understand the idea of a break in the ribbon. On the plastic bit that sits up against the ribbon/disc thingy, there are three points that press against the ribbon. I assume these make a connection with pressure, correct?

 

[sam am I]

Got my new multimeter yesterday. Checked the bottom of the board with neg probe, while + probe was on battery +. Got full voltage reading so the "ground foil" does appear to be grounded.

This "ground foil"?
Pic A



If so, No! That foil is directly connected (or suppose to) to the battery +...........It ISN"T ground, the black text is incorrect.

If you had your neg probe - on that foil area while the pos probe's + is connected to the battery +, then your reading should (has to be if connected properly) be 0'ish volts. It's a wire between the two testing points you used/listed.


Pic B

Follow the red wire seen above (see pic B) and where it connects to the board and look at my red boxed labels on both the above pic's............see?

They are (or suppose to be) the same points. Note that the red battery cable...........It hooks up the the board's spade connector and is solder directly (on the back side of the board) to that same foil in pic A above.....

The ground foil is mainly on the top of the board.......And again, but following black wires (see pic B) this time....THIS is a/your ground (battery -) test point (see pic C below) on the bottom side of the board.

Pic C

Still nothing when I check pins 5 and 7.

Correct.......Not until the throttle rotates on/about the flex face and off the center point (neutral/off position) should the relays turn on (you'll hear them click) and THEN the voltage will then be present on pin 7 UC3842. Drawing and theory of operation to follow in day or so.

On the plastic bit that sits up against the ribbon/disc thingy, there are three points that press against the ribbon. I assume these make a connection with pressure, correct?

Yes.......and using your finger nail, etc to press in of the flex will suffice as a substitute method to activate the comparitor (turn relays/power on the pin #7) if throttle isn't assembled.

 

[sam am I]

I'll add values, corrections, etc with rev's later.......

 

[sam am I]

Super simple test, eliminating all else..........Use a 12V battery connected just to battery + and battery - connectors (J3, J4) shown just above and leave the white wires disconnected. Then pinch the face of the flex over the dark area's (described several posts above).

This turns on the board (you'll hear both the relays click, relays turning on then turns on U2/UC3842).

If that works...

Now hook up a 12V light bulb (car tail or brake bulb) to white wires (motor+ and motor-), slide fingers in rotation while pinching or simply let off and pinch in different dark areas, the bulb will vary in intensity (PWM)..........

 

[jeepwm69]

This "ground foil"?
Pic A



If so, No! That foil is directly connected (or suppose to) to the battery +...........It ISN"T ground, the black text is incorrect.

If you had your neg probe - on that foil area while the pos probe's + is connected to the battery +, then your reading should (has to be if connected properly) be 0'ish volts. It's a wire between the two testing points you used/listed.


Pic B
.

I put + probe on battery +, and negative probe on the bottom of the board, right around where the black arrow is in that picture. I did have to puncture the layer of laquer on the bottom of the board. Showed 12.48 volts, which is what the battery shows with meter hooked directly to battery.

Follow the red wire seen above (see pic B) and where it connects to the board and look at my red boxed labels on both the above pic's............see?

They are (or suppose to be) the same points. Note that the red battery cable...........It hooks up the the board's spade connector and is solder directly (on the back side of the board) to that same foil in pic A above.....

The ground foil is mainly on the top of the board.......And again, but following black wires (see pic B) this time....THIS is a/your ground (battery -) test point (see pic C below) on the bottom side of the board.

Pic C



Correct.......Not until the throttle rotates on/about the flex face and off the center point (neutral/off position) should the relays turn on (you'll hear them click) and THEN the voltage will then be present on pin 7 UC3842. Drawing and theory of operation to follow in day or so.



Yes.......and using your finger nail, etc to press in of the flex will suffice as a substitute method to activate the comparitor (turn relays/power on the pin #7) if throttle isn't assembled.

I'll try the light bulb test. Guess this would work with a regular test light, right?