king meter J-LCD wont switch on

[Tazmantic]

Hi been a while since I was last on here or even ridden my bike due to many things but today I dragged her out to check her over. She had been stored in a metal shed that has been quite damp with the battery removed, the battery has been connected to the charger quite often to make sure it didn't go flat anyway I installed the battery and held the on (M) button nothing... checked the battery voltage 41volts (its a 36v battery) replaced the button cell in the king meter still nothing though I did notice if I held the on button and tapped the screen a few digits in the bottom R/H side lit up anyway here comes what I believe is the strange part, I removed the main battery and held the on button low and behold the display started up if only for a second then went off, so reconnected the battery once again nothing when button pressed removed battery and holding the on button it lit up again for a second.

This intrigued me so I connected the battery then disconnected again (obviously there must be some residual voltage stored in the system) I held the on button till the display lit up and quickly connected the battery, the display stayed on...

So the up and down buttons worked and the bike will run in walk mode (hold "down" button) pedal and the motor runs BUT the "M" button does not work so settings cant be set and the only way to turn it off is to disconnect the battery...

Any ideas anyone ???

P.S. I do have a Bluetooth module and if this is installed it only seems to show the speed on my phone when I'm sure before I could set the PAS and use walk mode etc

 

[Tazmantic]

Ok so after a little play with an old hover board battery thats giving out 27v if this is connected the J-LCD turns on fine and the "M" button works fine so its looking like if the voltage is over 36v it wont work so does this mean there should only be 36v coming from the controlled the battery connects to or the J-LCD should reduce the voltage to 36v but in either case how has this failed being sat in the shed with no battery connected

 

[Nealh]

King meter J has it own small watch battery, probably needs changing . Use a coin to open the rear access.

 

[Tazmantic]

Thanks for the reply but was one of the first things I did, made no difference.

 

[vfr400]

The main battery is probably switching off as soon as it's connected to the controller because the inrush current into the capacitor is tripping it. You can confirm that with a voltmeter on the connection between the battery and the controller. Disconnect the battery wires from the controller and measure the voltage on the battery side, then connect them and measure again while connected. If the voltage goes to zero when connected, then you need to check every upstream connection to see where the problem is.

 

[Tazmantic]

Hi thanks for the reply but when the battery is connected I've measured the voltage going to the king meter from the controller (black and red wires) and its 41v so I don't think the battery is switching off, what should the voltage be going to the king meter from the controller??

Thanks

 

[vfr400]

The voltage should be the same because the thin red wire going to the LCD is a spur directly from the thick red wire. It's completely independent of the controller, as is the LCD.

OK, so you've eliminated inrush as being the cause, but you need to measure the voltage of the battery wire when you attempt to switch on the LCD to see whether it collapses. If I'd doesn't collapse, you must have a faulty LCD.

You can test everything else and get some basic functionality by disconnecting the LCD and bridging the red and blue wires to each other and the two comma wires too. The comma wires are whatever is left after red, blue and black. Like that, you should get throttle operation and fixed level 1PAS.

 

[Tazmantic]

Thanks again, voltage stays at 41v when I try and power up the LCD so it’s looking like a faulty LCD then, just funny how the LCD powers up fine if I use a voltage of between 26v and 36v any more and it won’t turn on and also how it’s gone belly up just being sat in the shed

 

[Nealh]

Your post #1 eludes to being stored in quite a damp metal shed, it may be that the LCD is damp inside as well causing issues.

 

[Tazmantic]

Hi thanks for your reply and I was wondering that but it is well sealed and I couldn’t see any moisture inside when I replaced the battery also I have had it on the radiator so would think it would of dried out if there was any but maybe it has got corroded, might have to try taking it apart but I would of thought moisture/corrosion would affect it at all voltages

also in a manual on line for the king meter it says 24v/36v on the red wire

 

[sjpt]

also in a manual on line for the king meter it says 24v/36v on the red wire

I think the 24v/36v would be the nominal battery voltage. I don't think the real 41v was an issue; it would be expecting it

 

[Tazmantic]

OK so after another play I've pulled the LCD apart and I can see nothing obvious (not surprised really) but I have discovered with any voltage over 30v (not 36v like I said before) and the LCD wont turn on but If I frig it to come on with the battery shuffle I described earlier all seems to work except the "M" button bike runs PAS adjusts (though I've not taken it for a ride to see if it is different) 30v and under the LCD works perfectly but obviously its showing the battery as flat and bike wont run. So it is looking like the LCD has gone belly up and some internal voltage regulator is blown unless there is something else I can try/do??, Next question is can I get another one ??

Thanks

 

[vfr400]

I would say that it's defaulting to 24v operation rather than 36v. There are two things you can try:

First, disconnect the battery from the controller and short out the two wires on the controller side to discharge the capacitor, then reconnect everything and see if it works.

Second, reset the LCD back to its default settings as shown in the attached manual. if this isn't your LCD, show us what you have.

 

[Tazmantic]

Thanks for that and yes mine looks like that but the UP/DOWN buttons are above and below each other and the "M" button is at the bottom. Only thing I could get into was by holding the 2 arrow buttons (clock setting) then holding UP and M this brought me to PASS which the only password that worked was 0512 and then all I could adjust was wheel size and max kph, I couldn't get to any other parameters

Number on the back of my LCD is. 54800239-J1307-2016-09 if that helps at all and there is a white sticker that says 36L

 

[vfr400]

Thanks for that and yes mine looks like that but the UP/DOWN buttons are above and below each other and the "M" button is at the bottom. Only thing I could get into was by holding the 2 arrow buttons (clock setting) then holding UP and M this brought me to PASS which the only password that worked was 0512 and then all I could adjust was wheel size and max kph, I couldn't get to any other parameters

Number on the back of my LCD is. 54800239-J1307-2016-09 if that helps at all and there is a white sticker that says 36L

The sticker means it's a fixed 36v one, so I'm out of ideas now. maybe time to upgrade the whole lot with a KT controller and LCD3, which will be better than what you have. Costs about £70 from China.

 

[Tazmantic]

Thanks again, as you can probably tell it’s not used much so it’s really annoying it’s failed I suppose there’s no way of getting the same/similar LCD that would just plug straight in the green connector and work??

thanks

 

[Nealh]

Thanks again, as you can probably tell it’s not used much so it’s really annoying it’s failed I suppose there’s no way of getting the same/similar LCD that would just plug straight in the green connector and work??

thanks

For the price of a new KM lcd a new controller and lcd3 will be as cheap.
German sourced one.Web Translator (translatetheweb.com)

One could very nicely ask Hatti at Woosh bikes if they have any spare or old units available.

 

[vfr400]

There's a small chance that the cause of your problem is in the controller. Only buy a replacement LCD if you have checked that everything else still works, like I explained in post #7, otherwise replace both the controller and LCD.

 

[Tazmantic]

For the price of a new KM lcd a new controller and lcd3 will be as cheap.
German sourced one.Web Translator (translatetheweb.com)

One could very nicely ask Hatti at Woosh bikes if they have any spare or old units available.

Thanks so much any chance of some links to these items so I know exactly what they are please, and I’ll do some more testing then might contact Hatti.

 

[Tazmantic]

There's a small chance that the cause of your problem is in the controller. Only buy a replacement LCD if you have checked that everything else still works, like I explained in post #7, otherwise replace both the controller and LCD.

The wires to my LCD are...
Red
Black
Blue
Green
Yellow

so do I just connect red to blue and green to yellow? To test?

thanks