Power button not working - camera, volume and screen lock work fine

I have replaced my digitizer for the second time due to clumsiness - i have been very careful not to damage antennas and power cord. After re assembly the unit wouldn't power on with power button. I plugged it into charger and powered on with home button. Volume, screen lock and camera work - the power cable looks intact. Could the cable be broken and the other stuff still work? I have ordered a replaement power cable but any suggestions in the mean time would be appreciated. Cheers