ebike wont power on troubleshooting

[YonderGod]

A month ago I crashed my bike and broke my elbow, so I haven't been on it since then. I think I powered it on after the crash to make sure it still worked but I'm not 100% sure.

Today I tried to turn it on and nothing happens when I press the power button.
I have this kit: http://www.ebay.com/itm/371289491857?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT With 2x these batteries: https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=64439

The batteries have been resting at 3.8v and my charger is working so I don't think they are the problem.
I visually inspected all of the connectors and they all look fine.
I tried disconnecting everything except the batteries and LCD (which contains the power button) I'm not sure if it should power on without the motor and throttle connected.

Where do I go from here?

 

[d8veh]

Start with the LCD connector. The red wire carries battery voltage to power the LCD, so check with a voltmeter between the red and the black. If there's no voltage there, you'll have to follow that red wire back until you find where the voltage is interrupted. It's connected directly to the main battery wire via the controller's pcb, so check for battery voltage at the main battery connector to the controller, then at both points on the pcb, where the thick red battery wire connects and finally where the thin red to the LCD connects.

If you have battery voltage at the LCD connector, but the LCD doesn't switch on, the LCD is faulty and will probably need to be replaced, since they are normally sealed.

The LCD powers the controller. When it switches on, it sends the battery voltage back down the blue wire, which provides the power for the it.

 

[YonderGod]

I found the problem, the cable for the LCD got kinked and torn from my handlebars turning too far when I crashed. It works if I jiggle the cable, so I'll just have to cut it and re-solder it.

 

[999zip999]

D8veh way to go.