Dualsky 550 woes

[Chris56]

I run the above esc with the Dualsky 8.5T motor.

On friday night it was running fine but suddenly the car wouldn't move from standstill, but would if you gave the car a "push start".

Checked soldering etc - re-soldered all 3 wires, re calibrated, changed sensor wire however problem still persists.

Problem does not, however occur when I remove the sensor lead and run sensorless (but does run at a reduced rpm).

I did have a similar problem with another 550, except it was cogging and running sensorless didn't change anything. It was sent back and they exchanged it no problem, however im concerned that im having a similar problem with my second esc that has a top reputation amongst other drivers.

Any suggestions?