you could try this it might work
power on with no disc in dvd
wait for no disc display
press pause and enter
press 3 1 4 1 5 9
the word COdE or FF should appear on the display
enter 0 for all regions
press pause
press power off
wait 30 seconds then try any dvd
if this does not work you could try
pressing stop before you enter the above code
hope it works
Alan