I have been scanning slides and negatives for a few years with the epson 3200. Today I tried to scan some slides and the scanner will scan flatbed just fine but the slides do not scan any longer correctly. the light in the lid is on. attaching an image of the preview.
The most common reason is that the scanner is miscalibrating because you are not using the film holder, the film holder is placed incorrectly on the scanner bed or something is covering all or part of the calibration gap at the top of the film holder.