Fading digits on speedo

Here be mechanigeeks. Anything technical that is not a teething problem.
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Re: Fading digits on speedo

Post by 990Mongrel » Sun Mar 15, 2015 11:41 am

The pins on the LCD panel are useless so if you want a permanent fix you need to replace them.After many a patch up job I cut all the pins off.I used .7mm copper solid core strands from a piece of house power wiring.The copper wire was dipped in electric grease and fits nice and tight in the little sockets that the original pins went in.I had all the panels joined together with the LCD panel siliconed in position.Where the pins were broken off,I used my Dremel and ground a tiny recess in every terminal so the copper wire could sit in for positioning.I then pushed the copper wire through the plastic hole and into the socket,cut the wire level to the top of the LCD terminal and soldered it together.If you are not the best at soldering like me,just make sure there is plenty of solder joining the wire to the terminal and cleanup with the Dremel.If you plug the dash into the bike,turn on the ignition and all the digits stay on,that means one or more terminal soldering joints are touching.Just re dremel in between the solder joints until they are all separated.The speedo Has worked a treat for a while now.Down the track I will fit a race dash like a Starlane because I want a decent lap timer and shifting light but in the meantime I think the 990 dash apart from the formentioned problems is a very good user friendly and easy to read dash.Cheers.

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Re: Fading digits on speedo

Post by adcolor » Sun May 10, 2015 7:51 pm

NO! Not the Dremel!

Easy to use: solder wick. Not expensive, it is essentially flux (probably rosin) coated copper braiding.

http://www.solderwick.org/
http://www.ehow.com/video_4435742_remov ... 8ea4&pid=1
https://en.wikipedia.org/wiki/Desoldering#Solder_wick

Soldering is very similar to brazing or welding: clean, appropriate joint, appropriate heat, correct solder material, don't move the joint until it cools (freezes), clean residue (flux) off.

So the old sponge from the sink (or splurge and get a new small one with the green scrubby material on the other side). What $2 max?
Rubbing alcohol (or the real deal denatured alcohol). 75 cents at the store.
A tooth brush. No need to get any special color or nib count.
A moderate wattage soldering iron (this is not a plumbing job). $10-20.
Solder (there are grades more appropriate for hand soldering electronics -- versus plumbing, or machine soldering -- due to the tin/lead/antimony alloy ratios). $5-10.
Solder wick. $3-6? Lasts a long time, but look at the difference in cost of a short roll and long roll. Probably not much more for 2 or 3x the length. You don't need wide, ~1/8" will keep you from touching an adjacent solder pad/joint.

To solder: use the tooth brush and alcohol to clean the joints to be heated.
Heat the soldering gun.
Wet the sponge (thoroughly, then squeeze out the excess water). Should be soft to the touch. (this is for the cellulose sponges, not foam rubber).
Apply some rosin flux to the iron (just dip it into the can if it is the solid/wax looking version). Wipe it off on the sponge, then quickly wrap/wipe/scrub the tip clean with the scrubby side. Since the scrubby is plastic, be quick about it. Repeat as needed to get a clean tip.
Apply solder to the tip to 'wet' it or give it a shiny silver look.
Heat the solder of the joint with the tip until molten (if the hole is covered up), or add solder (called 'tinning') to the hole or two bare wires (you should still just be able to see the outline of the strands). Slide the lead of the item through the hole.

Remove the soldering iron tip, hold the joint stable until you see the solder 'flash' or freeze. Clean the joint with the toothbrush (due to the plastic bristles, give it a few seconds) and alcohol.

A good joint will cover all components, showing the outline of the strands of any braided/twisted wires, or outline of turrets, etc. 'Slobbering' more on is bad, not just in form, but can hide inclusions, poor joints, or even cold solder joints (plus it can make that area more rigid than it should be and cause a weak point to form in the wire right at the end of the solder. Always heat the joint until the solder is soft, not heat the solder stick/roll and drip it on.

A cold joint will appear grainy or dull compared to other joints around it. There might be a slight ridge around the pin or wire sticking through a solder pad. It will crack and cause intermittent opens, as well as corrode first.

I am sure there are more descriptive videos and write ups on how to solder/desolder. Some will be flight (aircraft/satellite) oriented (which I failed in two employer courses -- takes a very good hand to do that well).

Desoldering is similar: clean the joint, heat the solder and suck it off, or just use solder wick by pushing it over the pins and applying heat through the wick (I prefer to heat it first, then put the wick on it and reheat -- but that is not necessary). Then clean the joint as before (any solder remaining on the solder pad can be removed the same way).

And start from step one to solder:
tinning (really only needed for wire to wire joints; not needed to repair a pc board), cleaning, slide pin/lead through hole, tin the soldering iron, apply to joint, apply solder to the joint (NOT the soldering iron tip). Stop adding solder when a nice concave fillet is achieved (convex fillet means too much solder).

Sorry, I hope this is more help than confusing -- nothing here is too difficult for a person to do if they are sharp enough to hold the correct end of a screwdriver -- save an old hard drive, phone, motherboard, electronics device of some sort and practice on that. 30 minutes of hands on will leave you plenty good enough. And if it takes you longer, better to do it well than be left somewhere. Or pay someone else more. Plumbing isn't much different, but it requires a propane torch due to heat sinking by the pipes.

To protect you investment (for inline joints), get some glue type (sealing) heat shrink. Most heat shrink is 2:1 (2x the diameter of what it will shrink to). Save yourself some trouble and buy 3:1. It will fit a wider range of joints (slide over connectors, etc). Most electronics techs aren't even aware of it. Makes life harder than it has to be when assembling a wide range of sizes in a joint. Usually an issue when soldering a small wire diameter over a large diameter connector or crimp.
Mods: arrow exhaust, 2nd flies removed, plugged air injection caps, JC30-80 air filter, 44T sprocket, 80w high beam, short levers, weighted bar ends, Rox risers, remapped ecu, heated grips, horn, radiator screen, crash bar, skid plate, backrest.

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Re: Fading digits on speedo

Post by bigred » Sat Sep 24, 2016 8:42 am

Rangoonruns you are a legend!

Out for a ride this morning on my new SMT and the LED screen goes haywire, showing nothing, then a meaningless jumble of characters, then briefly what t is 'sposed to display.
Ride ruined I head home feeling very ordinary.

Two hours later I have disassembled the speedo, cleaned, glued and dielectric greased my way to what seems a good as new speedo!!

Shame on KTM that a 2013 bike with less than 10,000km on it should have a failing speedo.
When the going gets weird, the weird turn pro. - HST

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Re: Fading digits on speedo

Post by Rangoonruns » Sun Sep 25, 2016 8:09 pm

Still here and thank you !
My clocks have been trouble free since the rework. Still thinking about a multistrada but still finding the SMT fun every time I ride it so Ducati on hold lol
Enjoy your SMT ! There is nothing like it out there !!



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