No pressure on presser feet
 

I have a Bernina 1000 that my DH bought new about 25 years ago. One of many factors which caused us to choose it was how it sewed evenly over denim hems. I have only a little pressure these days. It stops when I piece cotton and it is very irksome. Does anyone know how to readjust it? There is a slotted knob on the top above the needle. I have turned it a little at a time in both directions and it makes no difference. Please help me if you can.
Thank you!

not familiar with that machine does it have a knob at the top of the machine? can you can press that down? I may be way off on this advice but my old machines have a pressure knob on the left!

If you've lost your instruction manual you might be able to find one online.

Try this link: http://www.bernina.com/en-US/Support-US

The Bernina 1000 doesn't give you control of the presser foot tension. However, if you haven't got any, it's usually because the presser foot shaft is gummed up with old oil. At the shop, we use a solvent to remove the gummy stuff, then remove the solvent and re-oil. Another factor to consider is the feed dog height. Are the feed dogs coming up high enough to pull the fabric through?

With a Bernina, you should be taking it in for service ever 12 to 18 months. I have a 1020 and a 1530.

It does sound like your baby is past due for service. I would bite the bullet and take her in for a much needed "spa" day.