lcd sw900 display lights up when battery powers on/connects
- Thread starter Bert8425
- Start date
What system is it? Prebuilt bike? kit? Pieced together from other stuff? Brand names / models?
Different ones work different ways, and some might have known issues like this.
However, the first place to check on most of them is the connector between LCD and controller, whcih may have corrosion or water between the battery power pin that goes from the controller to the LCD, and the "keyswitch" pin that goes to the controller from the LCD.
Different ones work different ways, and some might have known issues like this.
However, the first place to check on most of them is the connector between LCD and controller, whcih may have corrosion or water between the battery power pin that goes from the controller to the LCD, and the "keyswitch" pin that goes to the controller from the LCD.
Thank you for responding Amberwolf.
The system is a kit from Violamart. The lcd is sw900. Here is the link to the details https://www.ebay.com/itm/Electric-Bicycle-Kit-48V-1000W-Rear-Wheel-E-Bike-Motor-Conversion-Hub-LCD-Meter/222117405994?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
The last time it was working was the day before when I was measuring the voltage for the controller lights terminal with a voltmeter. I wanted to hook up light but wanted to know the working voltage. It was 32 and the computer is set at 36. Every thing was fine at the time.
I checked the connection from lcd to the controller with no results. The bike is garaged and dry. The kit is new.
The system is a kit from Violamart. The lcd is sw900. Here is the link to the details https://www.ebay.com/itm/Electric-Bicycle-Kit-48V-1000W-Rear-Wheel-E-Bike-Motor-Conversion-Hub-LCD-Meter/222117405994?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
The last time it was working was the day before when I was measuring the voltage for the controller lights terminal with a voltmeter. I wanted to hook up light but wanted to know the working voltage. It was 32 and the computer is set at 36. Every thing was fine at the time.
I checked the connection from lcd to the controller with no results. The bike is garaged and dry. The kit is new.
It is always helpful to post complete details like that, so wasteful speculation is avoided. 
The most likely thing in the case of the new details is that something was shorted by the voltmeter probes while checking the other pins (assuming you were checking on the LCD/controller connector; can't tell from your description), and either the controller or the LCD or both is now damaged, perhaps by battery voltage being shorted to a data line. If so, it's not likely to be fixable.
If the probing was done on a different connector, then it depends on what else was on that connector as to what might be damaged from a short of pins by a probe tip.
If the probing was done on a circuit board inside the controller or LCD, it depends on what is in that area as to what could be damaged.
If connectors were unplugged and replugged in the process of testing, pins could have been pushed out of the connector and not mating correctly, even if they "look" ok.
Or wires could be broken at the backs of connectors, where they crimp into the pins.
If you like, there are many posts about that particular LCD you can look thru to see if there is anything helpful (I haven't read them all, so I don't know if there is or not).
https://endless-sphere.com/forums/search.php?keywords=sw900&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=-1&t=0&submit=Search
Can't say if there's anything useful about the controller, since you haven't yet said what brand or model it is. (nothing on the linked ad shows the controller label or that info in text anywhere).
The most likely thing in the case of the new details is that something was shorted by the voltmeter probes while checking the other pins (assuming you were checking on the LCD/controller connector; can't tell from your description), and either the controller or the LCD or both is now damaged, perhaps by battery voltage being shorted to a data line. If so, it's not likely to be fixable.
If the probing was done on a different connector, then it depends on what else was on that connector as to what might be damaged from a short of pins by a probe tip.
If the probing was done on a circuit board inside the controller or LCD, it depends on what is in that area as to what could be damaged.
If connectors were unplugged and replugged in the process of testing, pins could have been pushed out of the connector and not mating correctly, even if they "look" ok.
Or wires could be broken at the backs of connectors, where they crimp into the pins.
If you like, there are many posts about that particular LCD you can look thru to see if there is anything helpful (I haven't read them all, so I don't know if there is or not).
https://endless-sphere.com/forums/search.php?keywords=sw900&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=-1&t=0&submit=Search
Can't say if there's anything useful about the controller, since you haven't yet said what brand or model it is. (nothing on the linked ad shows the controller label or that info in text anywhere).
I was afraid that I may have shorted something like you said. Now I will have to buy a new controller lcd combo. The terminals I probed where not connected to any lights yet and did not plug into anything but they were close enough to each other and recessed inside the plug. I have tried searching for the a dual mode controller like the one I have but can't find one. There are others but not dual mode 1000w. So anyway thanks you have more or less verified my suspicions. I will just use it like that until I get another.
Thanks again for your time
Bert
Thanks again for your time
Bert
