Purchased an Acorn 130 T700 from an estate sale. The batteries were virtually dead with barely enough voltage to power the display. I replaced the batteries and now it displays P1… I have not seen this before although I have been working with Acorn units since 2014.
Once I mounted the chair and pressed the armrest trigger the unit flashed a few lines on the display and has worked well ever since. If you have any information on Programming etc., I would be happy to know.