KT-LCD3 / display or speed sensor problem?

DynatechFan

Pedelecer
Oct 20, 2017
215
70
t'North
My Yose conversion has been working fine until this week when the bike got knocked over

The display now no longer shows speed and assistance no longer works - BUT display doesnt show zero speed even when moving - it is blank where the speed should be, all the other data fileds seem fine, though one or two "pixels" are missing

The bike fell over and the handlebars seem to take the brunt of the bash

Not particularly technical when it comes to electrics like this, I have pulled all the cables apart and put back together. FWIW the kit as installed without throttle and the walk assist still works

so what do I need ot do next? I am hoping it is the display, which I can swap out - if its the speed sensor in the wheel then thats a bigger deal (but why is it blank not zero?)
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
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I am hoping it is the display
Does sound like the display has been damaged in the fall and is causing the issues you mention. The fact you have Julet/Higo connectors makes it very difficult to test the rest of the system. I think it's unlikely your internal speed sensor has been damaged and I would expect to see zero on the LCD if it had. Do the buttons still scroll though PAS levels? Have you checked the PAS sensor magnet spacing? I have noticed Yose have replacement LCD's in stock at the moment if it helps.
 

Nealh

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The shock may have affected the display internally/damaged components inside.

Another remote possibility is a wire may be damaged, diagnosing julet sealed cabling is more time consuming and pin outs need to be identified.

You can check the PAS fitting, KT V12L may not be seated correctly or DL version check the magnet to sensor gap and the disc is secure.
 

Nealh

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Any KT lcd with julet connector will work.
Any pedelecer living in near to you may be able to help if they have a KT lcd , as it only involves plugging in to see if yours is faulty. Doesn't have to be lcd 3, a 1 or 2 will also work.
 

DynatechFan

Pedelecer
Oct 20, 2017
215
70
t'North
thanks folks, couldnt figure why the display would be blank not showing zero

The PAS seems fine, if I turn pedals in the workshop stand it does give a few W's. The buttons to adjust assist, disply items also works fine

I am nr Sheffield (working Manchester currently) if anyone could help out with a loaner display, if not will get an LCD3 of t'internet - best place to find one if not Yose?
 

Nealh

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DynatechFan

Pedelecer
Oct 20, 2017
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t'North
assistance no longer works in the sense of no 200W at PAS3 - just get a handful of watts that dont change with PAS setting
 

wheeliepete

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Feb 28, 2016
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assistance no longer works in the sense of no 200W at PAS3 - just get a handful of watts that dont change with PAS setting
OK, got yer, so it works in the sense that it's kicking in when crank is turned, but just not suppling much power. I guess that rules out controller and PAS sensor damage, just the display not providing the correct signal.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Try setting parameter C10 to y to do a system reset. I think you need a new lcd because the software is currupted but there's always a chance. I've had to replace a couple of these LCDs because of they developed software faults.
 

DynatechFan

Pedelecer
Oct 20, 2017
215
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thanks folks, just ordered the AliExpress item - seems the most likely solution here - fingers crossed, for lots of reasons; order worked? card details safe? customs let it through without gouging fees?

had another look at the screen when I checked the connector I have matches the advert - lots of dead pixels, the temperature reports wrong and all sorts of little things not quite right in the display :(
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
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Your order should be fine, you'd be very unlucky to pay any charges/vat etc. Might take 10-14 days to arrive. The first time I bought from China I had some worries about card details etc. now I consider it lower risk than paying over the phone for a pizza.:DIt's a good sign your display is getting worst, makes it more likely to be the problem.
 

Nealh

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No fees should arrive via RM or PF. My last order a BMS took only 6 days.
 

DynatechFan

Pedelecer
Oct 20, 2017
215
70
t'North
Still need help on this - been working away and not needed bike but thats about to change

Replaced the screen and it now works. Replaced the pedal sensor also.

But still zero assistance when pedalling - added the throttle and that works as expected

Dont know if I need to pull the wheel apart (or replace) or if it might be a broken wire / damaged controller - or if there are parameter changes needed

Thoughts?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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I'm confused now. You say, "still zero assistance", but you had some assistance before?

Did you put the magnet disc on upside down?
Does it work backwards? Which type of PAS is it?
Do the wire sequences match?
Why did you change it when there was nothing wrong with it?
 

DynatechFan

Pedelecer
Oct 20, 2017
215
70
t'North
okay, quick precis so you dont need the rest of the old thread

Yose kit worked perfectly, was running without throttle but all the other sensors etc
Bike fell over, hard impact onto concrete to left side - display pixels trashed, no assistance
Swapped out display - no change
Checked cables / connections multiple times cant find any issues
Swapped out PAS - no change (it is a splined PAS, impossible to put on wrong)
Added throttle and it (throttle) works as expected (more throttle = more power) but still no pedal assist. At least I know the motor works and assume its a sensor or cable problem still

So - do I pull the wheel apart? Swap out controller (dont have one)? Or just give up looking and buy another Yose wheel kit and have lots of spare parts?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Are you saying that there's still a problem with the display after replacing it? If so, that can only be its cable because it works independently from everything else.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Testing with Julet connectors isn't very easy, you need to try and pin point what is wrong. Having replaced lcd and pas and with a working throttle and motor, it suggests the controller or the trunk cable is at fault.
If you have a multimeter you can try and test the pas wiring to see if the controller is supplying voltage to it, it will mean baring the pas wires or trying to come off the pcb direct.
 
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DynatechFan

Pedelecer
Oct 20, 2017
215
70
t'North
thanks NealH, done endless multimeter checks but awkward to do as you say. No expert here but guessing it can only be cables, controller or "something inside" wheel issue - the controller was in a soft frame bag so wouldn't expect it to have received much shock, but I cant find any cable issues, and I dont know if there are in wheel sensors/stuff that would cause this behaviour

Bit of a long shot, anyone one near Sheffield able to loan me a controller to swap in ?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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If the hub works ok with the throttle then there is nothing wrong with the hub.
An innocuous falling over can cause damage to wires by way of stretching and pinching them and possibly damage to a controller if the shock is severe enough.
Check the pas wire/ connector from the controller for damage and open the controller and follow the pas connections to the PCB in case a wire has been tugged and come a drift.
The swapping out of a controller to try is a good idea if you can find someone to temporary loan/swap one out.

Like VFR I tend to opt for the older SM connector type of controllers, so much user friendly for testing.

If I had a 100% Julet set up, for testing I would get some 3 pin Julet wired tails M/F and splice in a 3 pin SM connector tail. Then simply disconnect the system julet connection and place the test/ wired section in line to carry out wire testing.
 
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