Makita DUN500

[Spoonz]

Hi guys, hoping someone can help me out ! 
 

Trying to fix my long reach hedge cutter but this is my first battery tool breakdown so I’m a little lost. 
 

I changed the gear housing due to it being worn and causing issues the the drive sprocket alignment and since putting it back together I’ve had the following issue. 
 

I’d press the ‘throttle’ and it works for perhaps 5-15seconds before stopping and lights on the handle flashing, producing the warning code for overload.

 

I thought perhaps I hadn’t put the cogs back together correctly but I’ve just changed the rotor assembly and while it was removed it didn’t rotate freely. I’m abit stuck with it so any advice would be greatly appreciated!