How to mend my Olivetti ECR 7100?

That's common. Usually the rack has failed in the printer. They are a very low duty printer and suffer lots of problems if used in heavy situations. You don't even repair the printer. It gets chucked in the bin. Best advice is sell it once it gets replaced under warranty and buy a thermal printer machine for a fraction more cost. Much better machines!

Registerman
February 2015

If you are in the UK, you should get the retailer who sold the till to you to sort it out under warranty.

Trevor
February 2015