I have a 7570 and there is a small wheel under the front screen that adjusts the screen contrast. It is very hard to see if you are not looking for it, I do not know if that is on your machine but it is worth looking for, maybe it got accidentally turned if it has one. I also have the older Pfaff 1475 and just short of selling a kidney to pay for repair costs I would have mine fixed. I just used the 1475 to do a home dec project that my newer machines would not sew through.