Techniques are described for collecting feedback on a display comprising a plurality of emitters arranged in a column. Each emitter is driven by a respective emitter cell that generates a driving current for the emitter based on digital data or an analog representation thereof. The digital data or analog representation is sequentially shifted through the entire column. An electrical signal associated with a last emitter to be driven based on the digital data or analog representation is measured, along a feedback path formed by selectively opening or closing a first switch and a second switch, which are respectively connectable to an anode and a cathode of the last emitter. Since each emitter cell contributes to the electrical signal, the value of the electrical signal is indicative of whether there is a problem with an emitter cell somewhere in the column. The subsequently driving of the emitters is adjusted accordingly.