Could be the battery.
Put the Scooter on a block so the rear tire is raised. Remove the standing plate to reveal the battery compartment.
Charge the Unit completely
1. Using a multimeter measure the voltage across the batteries. If the voltage is below 20 volts batteries are dead - Replace batteries.
2. Now for a running test. Turn the throttle and spin the rear tire to preform a kick start. Still measuring the voltage. If the voltage is Below 20 volts or if the voltage drops quickly batteries are dead - Replace batteries.
3. If the voltage is remaining around 24 volts for a long period - then you could have connector problems, clean and tighten all connectors.
I use a fiberglass electronic cleaning brush, as contact cleaners leave residue that interfere with electrical connections.
The control module is simple and can be replaced with only a 24 volt relay without the kick start feature or Brake. If you want the brake then you can use two 24 volt relays still no Kick Start.
For those of you who know electrical, below is circuits I developed to replace the controller. This diagram will also give you a better understanding on the Razor circuit.
NOTE : This is not a schematic diagram of the Razor E100 Control Module. I designed this circuit. for my Great Nephew's Scooter.
1. The Brake is a normally closed switch that opens when you squeeze the Brake handle.
2. The throttle is two normally open switches that close when you turn the throttle.
3. The Kick Start circuit is described in the Diagram below.
4. The resistors values may need to be tweaked for best performance.