A couple of suggestions…
Download and run Parmon to check the operation of your PC’s Parallel Port is OK.
http://www.geekhideout.com/parmon.shtmlCheck continuity of your supplied LPT parallel port cable and that Pin 1 connects to Pin 1, Pin 2 to Pin 2 and so on.
Check that the Emergency Stop button on your controller is not pressed in. (this may sound stupid but some have been there).
There are many problems associated with these Chinese imported machines mainly due to lack of quality control during manufacture. With the power disconnected take a look inside the control box for bad connections, burnt components, wires off, etc. – take your time and visually examine in detail.
Tweakie.