V2 throttle no display no led! Help!

I’ve just bought a used unit Version 2. After connecting the battery, turning on the main power switch the pros twitch normally and being as it should. Can’t seem to arm the motor, no led on throttle arm button and display for battery % bank. Below is a pic of the throttle, after opening it saw a lose wire not sure where it goes. Any input will be helpful.
Thanks Guys!

The white wire looks to go to the ESC signal and connected to D10. However that shouldn’t affect the unit turning on.
Since you’re on the first generation controller its probably worth upgrading directly. PM me and I’ll see what I can do to help with that.