remove speed from samebike 20lvdx30

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
You shouldn't buy a replacement controller unless yo have tested your present one and found the fault, otherwise you might be wasting your time and money. See post #24 here.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
7,467
2,843
56
West Sx RH
Any suggestions for this controller replacement? Would any unbranded chinese controller for 48V and 350W fit? Mine is dead after a wet road ride a few days ago. I'd better have that silicone sealant applied, at least on some parts of the compartment..
You can try what ever controller you like but likelihood is that your lcd display functions won't be fully compatible due to firmware/protocol commands.
If replacing a controller with a different make buy it long with the same make of lcd.
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
You shouldn't buy a replacement controller unless yo have tested your present one and found the fault, otherwise you might be wasting your time and money. See post #24 here.
Thanks. I checked MOSFETs. Battery negative to blue/yellow/green are all at exactly 3.17kΏ. Battery positives are around 26kΏ. Do these numbers make sense?

Could you help me a bit with measuring 5V on the connectors? There are 6 cables for throttle in total, connected like this:
30542
Should I power on the bike, disconnect both throttle connectors and measure voltage between red and black wires on controller side? I tried with no luck.

It seems that controller is just turned off when orange/red/white connector is disconnected (judging by the voltage on some other connectors, that normally have 53V). So I left orange/red/white on and disconnected only the second one, that is black/green/orange. Tried measuring the voltage between black and orange wires and it’s only 0.55V. Does that make sense?
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
The brown and yellow wires are the switch on the throttle, the green one on the same connector is battery voltage for the LED indicator lights. Red and black joined to orange aand black are the 5v wires. that leaves the blue to green is the throttle signal wire (1v to 4v).

To measure the 5v, the controller has to be switched on and the throttle disconnected. If you short the middle pin (green) to the 5v (orange) one, the motor would burst into life, so be careful. I'd pull out the hot-melt glue from the back of the connector and shove my probes up there. If you have 5v, you should check again with the throttle connected, and then you can check what throttle signal you get by measuring between green and black while you open the throttle.

Your MOSFET resistance values are probably OK. I have seen values like that before, but not often. Normal is around 7K to negative and 14K to positive, but it depends which MOSFETs are used. If there's any trouble, you nearly always see a significant difference in values within each group of three. At the moment, I'd be looking elsewhere for your problem.

I'm going to bet that you have no 5v, and I think I know why.
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
To measure the 5v, the controller has to be switched on and the throttle disconnected. If you short the middle pin (green) to the 5v (orange) one, the motor would burst into life, so be careful. I'd pull out the hot-melt glue from the back of the connector and shove my probes up there. If you have 5v, you should check again with the throttle connected, and then you can check what throttle signal you get by measuring between green and black while you open the throttle.
So I left orange/red/white to green/yellow/brown connected, enabled the controller and measured the voltage between orange and black, which you said are 5V wires. It was only 0.55V.
However, for some reason everything (engine when throttle is pressed) starts working randomly from time to time for short periods of time. I measured again the voltage between orange and black wires when it was working. Got 5V instead of 0.55V.
So it's certainly a 5V problem on throttle connector.
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
There must be a short circuit somewhere. disconnect the red, black and blue connector and measure the 5v again on the controller side. If it stays steady at 5V, a new throttle is probably the easiest option.

 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
There must be a short circuit somewhere. disconnect the red, black and blue connector and measure the 5v again on the controller side. If it stays steady at 5V, a new throttle is probably the easiest option.
Wait. There is no 5V on controller side. It only has 0.55V. I thought it means that the 5V regulator is blown and the solution is to replace it inside the controller? Or is it in the throttle?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
Wait. There is no 5V on controller side. It only has 0.55V. I thought it means that the 5V regulator is blown and the solution is to replace it inside the controller? Or is it in the throttle?
Sorry, I misunderstood you. There must be a short on the controller side somewhere. Look for anywhere the cable makes a tight turn or where a cable tie holds it too tight.
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
Sorry, I misunderstood you. There must be a short on the controller side somewhere. Look for anywhere the cable makes a tight turn or where a cable tie holds it too tight.
Let’s have a look inside:
A0B050C3-F458-4B81-A0B3-056EB22000E8.jpeg
2844A5B3-2A50-4FE1-BA9E-47B7FAB557BD.jpeg

Not sure what to check. Cables seem ok. It started shortening after quite a bit of water got into compartment.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
It can be any cable that carries 5v anywhere on the bike, like PAS cable or motor cable.

While you have the controller open, connect the throttle switch connector (brown, yellow and green) and the battery. Switch on and measure the 5v on the PCB to see that it stays steady. that will confirm a short somewhere else.
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
It can be any cable that carries 5v anywhere on the bike, like PAS cable or motor cable.

While you have the controller open, connect the throttle switch connector (brown, yellow and green) and the battery. Switch on and measure the 5v on the PCB to see that it stays steady. that will confirm a short somewhere else.
Throttle has the same 0.55V on the board.
Checked PAS connector as well - the same 0.55V.
I also disconnected HAL sensor. It had quite a bit of mud inside. Voltage is 0.32V between red and black, 0.55V from black to yellow/green/blue and 0V from red to yellow/green/blue.
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
I don't understand what your saying. all you need to do is disconnect everything from the controller, then connect the battery and throttle switch so that you can power up just the controller. Do not connect the throttle. measure the 5v on the pcb.

If it's 5v, the short is somewhere outside the controller. If it's not 5v, your 5v regulator must be blown. If the 5v is intermittent when you wiggle the wires or bang the controller, you have a dry joint on the pcb.
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
I don't understand what your saying. all you need to do is disconnect everything from the controller, then connect the battery and throttle switch so that you can power up just the controller. Do not connect the throttle. measure the 5v on the pcb.

If it's 5v, the short is somewhere outside the controller. If it's not 5v, your 5v regulator must be blown. If the 5v is intermittent when you wiggle the wires or bang the controller, you have a dry joint on the pcb.
Right. That’s what I did. Wasn’t able to get no where close to 5V. So it must me a blown 5V regulator. You mentioned in the other thread that it’s an easy fix. How can I replace it?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,723
372
Basildon
They only cost a few pence. It's athree legged device, like a transistor, probably like a little pellet, but could also be the larger flat type like a MOSFET. The markings on it will probably include the characters 05.

The battery voltage comes into the controller and goes through the large resistor/s to the 12v regulator that's flat like a MOSFET, then a branch goes from thereto the 5v regulator, so you should find it if you follow that route. Take the numbers off the 5v regulator and type them into an Ebay search -just the string that includes the 05, not all the markings in the other rows..
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
They only cost a few pence. It's athree legged device, like a transistor, probably like a little pellet, but could also be the larger flat type like a MOSFET. The markings on it will probably include the characters 05.

The battery voltage comes into the controller and goes through the large resistor/s to the 12v regulator that's flat like a MOSFET, then a branch goes from thereto the 5v regulator, so you should find it if you follow that route. Take the numbers off the 5v regulator and type them into an Ebay search -just the string that includes the 05, not all the markings in the other rows..
Ok, so must be this little thing here:
61186685_602074976963503_3591750724372922368_n.jpg

Does this look like a good replacement? https://www.ebay.com/itm/Diodes-Inc-AS78L05ZTR-E1-Linear-Voltage-Regulator-100mA-5-V-A-5-3-Pin-TO-92/163124205787?hash=item25faf5d8db:g:kW4AAOSwxdRbNmVu
 

picusiaubas

Pedelecer
Jan 28, 2019
25
1
Lol. It's still 10x cheaper and easier to replace than buying a new controller, so not a big deal. There are much cheaper options from China, but I would prefer UK seller because of faster delivery. Thanks a lot for your help!
 

bucio

Finding my (electric) wheels
Jan 15, 2019
7
0
i made the same moves only holding brakes and now i have 37 on screen 25 real ..... i dont understand if there is a way to go to 30 real
 

Erisaman

Finding my (electric) wheels
Jun 12, 2019
6
1
Hi, I know I’m rather late to the party, but I found this thread 10 minutes ago and immediately registered on the Forum.

You guys certainly don’t shy away from exploring your bikes - whilst I’m a total newbie but willing to learn. 'Considering' the speed limit was going to be my first - well .... second task - on my 20LVXD30. I say second because the first will be unboxing and assembling, charging the battery and giving it a whirl around my home.

Yes, I had word this morning that my new toy has been shipped out of Poland so I’m now awaiting delivery. It’s coming courtesy of G/best.

I’m in the U.K, in sunny S/West Wales .... right, enuff from me for now - hope to keep in touch and follow your successes.

Thank you for your patience.
 
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picusiaubas

Pedelecer
Jan 28, 2019
25
1
That's the one. Seems a bit expensive though. You should be able to get 100 for that price.
I’ve received the 5V regulator and replaced it on the board. Sadly, it didn’t have any effect. Still has 0.53V.
Maybe it was not the regulator, but the blown cpu (problem number 4)?
 
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