***if you are planning on repairing MFD READ THIS***

[ki5pm]

Does anyone know what the 2 adjustable potentiometers on the back of the MFD display circuit board do?? (Polaris SLTX1997)

The two Potentiometers are used to calibrate the pressure transducer for the speedometer function.
On the MFD's that I have repaired I have not found these adjustments to be out of calibration.

[nitrosportman]

The two Potentiometers are used to calibrate the pressure transducer for the speedometer function.
On the MFD's that I have repaired I have not found these adjustments to be out of calibration.

so both are for the pressure transducer did you finally get a chance to play with them? i may jack with them some more sometime this weekend

also i think we need to update this and cut the case further back to avoid cutting the button ribbons anyone agree?


i've also found that the standoffs for the screws can get deformed making the lcd still seem dim you can trim down the standoffs with a hobby knife slightly giving you a little more "squeze" on the connector going between the lcd and circuit board

[ki5pm]

so both are for the pressure transducer did you finally get a chance to play with them? i may jack with them some more sometime this weekend

Both pots are used to adjust the linearity of the pressure transducer. one for the lower end and the other for the upper end. Adjusting one affects the other. It's back and forth many, many times to adjust the linearity correctly. Also a very accurate pressure gage should be used. I use a mercury manometer calibrated in MM/hg. Then convert MM/hg to PSI.

Again, I suggest these pots NOT BE TOUCHED unless you know for sure that the problem is in the MFD and not elsewhere. K447's signature link has the info on the correct pressures for calibration purposes of the speedometer display.

also i think we need to update this and cut the case further back to avoid cutting the button ribbons anyone agree?

K447's signature link also describes exactly where to make this cut. The cut must be made so that there is still surface area on the rear of the MFD to seal the unit after repairs are made.

i've also found that the standoffs for the screws can get deformed making the lcd still seem dim you can trim down the standoffs with a hobby knife slightly giving you a little more "squeeze" on the connector going between the lcd and circuit board

[ghostridermb]

Hey guys bought this 2000 SLH700 redid the motor hooked up the battery the MFD started flashing shows all displays the red light also flashes then it freezes on 01CR I have took a video of this to see if anyone could help. I have had the whole mfd apart and I cleaned it is there anything else I can try? What is the small fuse in the electrical box for? Seems to keep blowing thanks!!!

http://www.youtube.com/watch?v=pObjqEf1aSE

[nitrosportman]

direct link please i can't find it

[ki5pm]

direct link please i can't find it

http://www.greenhulk.net/showthread.php?p=1249604#post1249604

[K447]

How to cut open a Polaris oval MFD to repair faded digits

I cut JUST BELOW the black plastic rim instead of between the black rim and the clear front.

Hey Callan. I am a little confused on exactly where you cut open the MFD. See the attached pic, I put some arrows in there on a few places I thought you may have meant.

Thanks

Turk

I thought it might be helpful to update this thread.

The optimal place to cut into the MFD case is indeed right behind the front panel plastic flange.

The cut through the black plastic only needs to be a couple of mm deep. The outside edges of the circuit board are right inside, so your cutting tool may touch it at times. Make several passes, cutting a little deeper each time. You will get a feel for how thick the plastic is as the tool breaks through.

Update: Using a flush cut hand saw works better than the Dremel cutting wheel method.
The Dremel method does work but it makes a wider cut and there is more risk of the cutting disc grabbing the plastic or going too deep.

Take your time and hold both the display and the Dremel tool firmly. The spinning disc has a tendency to stick or grab in the slot. Use a slow Dremel speed. I use the very first or second speeds.

The only places where the cut depth is super critical is right below the two front panel buttons. I tend to cut shallow for about an inch just along there near each end and once the front panel has been mostly severed everywhere else, a little flexing usually breaks the remaining plastic near the buttons and the front section becomes free to pull away. If there are a few spots where the plastic is still hanging on deft application of a flat blade screwdriver can crack it free. Do not stab towards the insides of the unit. Aim the screwdriver along the crack, starting from a corner.

Photo from a recent MFD repair for the classic faded digits problem.




For this MFD cut I used the Dremel EZ476 1 1/2-Inch EZ Lock Rotary Tool Cut-Off Wheels For Plastic



This gives you an idea of how shallow the cut should be. Just enough to breach the plastic wall.





In the background you can see the classic Dremel ceramic cutting wheel, which I have also used successfully to cut open several MFD.
I think I now prefer the plastic EZ Lock cutting disc, but the classic disc also works well enough.


Click here for the next steps

For reference, here is the classic photo from the original threads showing the correct Green Arrow cut location.
Note that the actual cut groove shown in the photo is NOT the correct place to cut. That groove was an experimental early test cut, now we know where to cut.

[Mr. GP1800]

Ok guys, I am going to let you in on a little secret. I am a cabinet maker/woodworker as a career and I have the perfect little saw for cutting these open.

Its a flush cut hand saw. Its designed for cutting off protruding dowels or similar pieces flush with an existing surface. The secret to this saw is that the teeth are only set in one direction, so as not to mar the surface of the piece you are cutting flush to.

It works beautifully on the MFD cases, and I can have one open in about 2 minutes. Best part is that it makes a very straight and clean cut, making reassembly and sealing very easy.

I use black RTV to reassemble the case. Works beautifully, and if it never needs to be cut open again, all it takes is a sharp knife blade.

http://www.acetoolonline.com/Stanley-Hand-Tools-20-331-4-3-4-Flush-Cut-Saw-p/stt-20-331.htm?utm_content=Stanley20331434X23PtFlushCutSawWithFlexibleBlade&gclid=CK-vqviq1roCFQpnOgodtUEAXg&utm_source=googlebase&utm_medium=cpc&utm_term=Stanley20331434X23PtFlushCutSawWithFlexibleBlade&utm_campaign=googlebase&site=google_product_listing_ads

[K447]

Bravo, I like that method!

I shall put this on my shopping list.

[Mr. GP1800]

Dave has seen me cut a few open. He will tell you how good it works

[ki5pm]

Thanks Bryan. It's always nice to get this kind of information from a professional.
I will get one and try it out next time I cut one open.

[K447]

Continuing on with the process of repairing faded digits on my MFD ...

Here is what it looks like once you have successfully cut the case away from the front portion.

You can clearly see how close the ribbon cables are to the lower edge of the case.

Unplug the two connectors from the circuit board. Make note of how they were attached.
Do not yank the orange wires out from inside the case. The sensor sealed into the back should remain plugged in to its connector.

Carefully slide the thin ribbons out of their connectors. Do not tear or crush these ribbon cables.



With the ribbon cables out of the way, remove the four screws that hold the circuit board in place.

[K447]

Gently lift the top edge of the circuit board. You will see the pink rubber contact strip underneath.

It normally is stuck to the underside of the circuit board, so lift the board slowly as it peels itself away.



Now the circuit board can be lifted off.

You can see the row of metallic contacts that touch the edge of the rubber strip. You will be cleaning these contacts.

Lift the clear plastic frame away from the back of the LCD panel. Make note of which edge has the slot for the conductive rubber strip.


Gently lift and peel the rubber strip up and out.

[K447]

I use a zero-residue electronic contact cleaner spray. Make sure the cleaning product you use is safe for plastics, will not leave a residue, and is intended to clean electronic contacts.


An alternative is to use alcohol and a cotton tipped swab to clean the contacts. Just be sure to remove any stray cotton fibers afterwards. Do not use alcohol that has oil or other contaminants.

Spray it into the groove on the back of the LCD panel where the rubber strip was. Do not scrub in there, the contacts are a very thin film coating on the glass.


Use the same cleaning spray to clean the row of flat metal contacts on the circuit board. Here you can use a toothbrush or similar to give them a little scrub. It should not take much scrubbing and a quick blast of spray cleaner to brighten up the contact surfaces. Set it aside to dry.

I use the same cleaner spray to clean along the two long edges of the rubber strip. The thin black center strip is actually hundreds of conductive carbon 'wires'. Do not get too aggressive with cleaning this or it will be damaged.

After a few minutes everything should have dried off and be clean. Drop the rubber strip down into its slot in the plastic frame. Wiggle it a little to be sure it is settled, but try to keep your oily fingerprints off the conductive edges.


Position the circuit board back onto the four plastic bosses. Make sure the board has settled down onto the shoulders and is fully seated.

Reinstall the four screws. Do not cross thread the screws and do not over tighten. Just snug is all it needs.

Reinsert the ribbons into their connectors. Be sure to fully insert each.

This photo shows the ribbon cable NOT properly inserted.


This is what it looks like when properly done

[K447]

Plug the two connectors back in.
Be sure to get the pins aligned, not offset by one pin left or right.



Check the plastic case for plastic cuttings or sharp edges. Use a knife to trim off any excess so the case seam will be clean when put together.



Now that the display is put back together, but before you glue it closed, I suggest you test it.

I used a workbench test rig to power it up but you can just plug it back into the connector on your watercraft. If it does not wake up promptly when plugged in, press the Mode button for a couple of seconds. It should wake up and look like this.



Tip: Use the same non-residue contact cleaner to spray into each of the holes on the wire harness connector before you plug it into your freshly repaired display. The cleaner should dissolve any dried up dielectric grease that may be in there and remove any dirt. It is supposed to be a sealed connector when installed, so it shouldn't be very dirty to begin with.