If you have access to a 2nd ebike of the same voltage and with the same type of connectors you can quickly determine the part that is not functioning in some cases.
DO NOT test 2 ebikes together if they are different voltages.
48V Ride1UP ebikes: Core-5, 500 Series, 700 Series, LMT'd are all 48V ebikes with 48v batteries, motors, and displays. All of them also use a 9-pin motor cable coming from the motor.
36V Ride1up ebike: The Roadster V2 is a 36V ebike with a 36V display, battery, and motor. It also has a 9-pin motor cable coming from the motor.
Whether it is a friend's, your local shop, or you happen to own 2. You can do advanced troubleshooting by testing components of bike A with components of bike B.
In some instances, this can pin point an issue with a certain component quickly. The correct replacement part can then be sent with confidence it will resolve the issue. The connectors must match. See display example below at the bottom.
SECTION 1: Motor not working?
Testing Motors with 2 eBikes
It is important to connect the right components and avoid doing the opposite. If you test what maybe a fried motor with the working bike, it may damage the good controller from the working ebike. However, if you connect the the display and controller from the non-working bike with the working bike motor, there should be no chance of these items damaging the working motor.
For example, if Bike A is our working bike and bike B is our error bike and the motor is not working. It would be best to park the 2 bikes right next to each other, facing opposite directions, so the rear right chain stay is directly next to the other.
In this example, we would disconnect both motor cable at the chain stays. We would when connect the motor of Bike A (working bike) to the 9 pin cable that leads toward the front of the bike, connecting it to the the controller Bike B (error or non-working). At this point, it it helpful to have a friend. They can carefully raise the rear wheel of Bike A (working) and you can turn on power to Bike B and then carefully use the throttle to test the motor. Make sure the wheel comes to a top before they lower the rear wheel and that you turn the bike off as soon as you are done testing.
SECTION 2: Display not working?
Testing Displays with 2 eBikes
Another easy test is to swap the displays. You can carefully remove the display and connect it to the other bike. Make sure if when you install the display on the handlebars, do not over tighten the screw. It will brake the plastic. Only tighten it gently until you can feel the display is held properly in place.
For example, the 500 Series and 700 Series Displays both have the same display connector if you follow the wire from the display, to the first connection. Both are green higo with 5 pins.
However, the CORE-5 and LMT'd have a different connection, it is a jst-sm connector with 5 wires shown below: