We have studied the shift in Fermi Energy E(F) after prolonged light soaking in undoped hydrogenated amorphous silicon in order to find the position of negatively charged dangling bonds D- in the gap. The result show that D- should lie lower than 0.75 approximately 0.80 eV below the conduction band edge which is in agreement with photothermal deflection spectroscopy (PDS) and other results but contrary to those of photomodulation spectroscopy and others.