| Friday, 24.1., it was noticed that the modules are graded as 'C' in similar fashion. Module is graded A/B at +10 degrees and then graded C at -20. The reason for grade C was that the trimming procedure was not successful on at least one of the ROCs on each module. This problem was further investigated on 27.1. Wolfram suspected that the problem lies in zero suppression mode since the pixels with failed threshold comes in groups of four pixels. The corresponding DAC 'ctrlreg' was set, as recommended, to 17, during previous tests and after changing it to 9, the problems at -20 seem to be gone. This will be further investigated. |