Ryobi ERT-1150VN manual and spares
My exact same router quit on me today after intermittent lack of power.
I carefully stripped down the machine (carefully) and did a continuity test on all the wires, i found that one of the main motor coil wires had no continuity so i completely disassembled the motor assembly and found one of the main coil wires had broken at its terminal. A quick bit of careful soldering, reassembly and it now works perfectly.
If you strip down the machine it will void your warranty but if you are very careful
it is really not too difficult.
I had to loosen the two black wires from where they connect to the two blue wires to remove the housing, remove the circlip from the leg to remove the base plate, remove the brushes and the four long screws to remove the rotor, remove the two long screws to remove the outer coil.
Be careful to carefully tighten those two longest screws as they go into plastic threads.
I hope this is some help.