I have a 2002 & a 2003 Brother ULT …both sew/embroider machines, that cycled on and off, sewing only 2-3 stitches before repeating the on/ off, on/ off cycle. I took the 2002 , my favorite, to local repair and he cleaned the contact points. No fix. So I then I drove almost 200 miles RT to nearest “brand” shop where I was told the power supply unit was the problem, bu “unfortunately the part is no longer available”. Believing the dealer I bought from could perform magic, I drove even farther only to have contact points cleaned again. The machine sewed again…for approx 6 hrs before it died..dead! I’m still sewing on my 2001 ULT, and I’ve considered moving its PSU to the 2002 model, but if something goes wrong in the transfer, I’ve lost another machine. Alas! I’ve searched ‘high and low’ for the Brother or Babylock PSU— to no avail.
I suspect your friends machine may have the same problem, but it’s worth asking for the contacts to be cleaned before giving up.
So sorry. Good luck.