I had the same problem which I managed to solve. The electro magnet that holds the toast lever down takes its power from a poor joint.
Remove the bottom of the toaster. You will see 2 wires encased in a heat proof sleeving going from the small circuit board. One of these wires dissapears up inside the heating element board about mid way along the board. You will now have to remove the metal covering by twisting 6 tabs. This is best done by taking off the black knobs you use to push the toast down - if you can - I couldnt, so I had to use long nosed pliers to bend the tabs and then with difficulty, remove the metal cover. YOu should now see the terminal that the wire is connected to. It is this connection that fails either between the wire and coonnector or connector and heatin element on the reverse side. I put a small bolt through the hole and used a nut to tighten the pressed fitting. I didnt use solder because I thought that it would just melt!
Anyway, my toaster worked after that. Russell Hobbs failed to give me any advice at all.
I hope that has helped.
Neville
Welwyn Herts