Have you had the error message, Wiper Error? If so, chances are you need a new Brother PR fixed knife & clip. The message will generally appear when your fixed knife is blunt. Alternatively, it may be jammed with loose thread. So it makes sense to check the knife on a regular basis. Keep it clean and replace it when it causes problems.
Wiper Error Message
Look at the photo showing the fixed & moveable knife base. This was removed from a Brother PR. The machine had come into our workshop for service and repair. As part of our service check list we always remove the needle plate, and the knife base. You can see all the old threads caught around the fixed knife. This will hinder it and possibly cause the Wiper Error message. Over time, the knife will become blunt and should be replaced.
Fitting the Brother PR Fixed Knife & Clip
Fitting the knife and clip is a simple job.