A method of maintaining an initial bias of an x-ray detector (12) includes setting the initial bias of the x-ray detector. Operating state of a readout circuit (30) is altered. A photodiode common contact voltage potential is adjusted by a data line drift amount to approximately maintain the initial bias. An x-ray imaging system (10) includes a detector (12) that has multiple pixels, multiple data lines (50), and a common contact (62) that is at a common contact voltage potential. The readout circuit (30) is electrically coupled to the data lines (50) and has a multiple power states. A controller (36) is electrically coupled to the readout circuit (30), detects a change in operating state of the readout circuit (30), and adjusts voltage potential of the common contact (62) in response to the change in operating state.