ceramic hob has locked out lost manual scholt ceram hja 1613?

1. Turn on the hob using the main switch (l)
2. Simultaneously touch the (+) and (-) keys for at least 2 seconds.
3. Touch the (-) key again
4. All the hotplate display will show L. during period of unlocking, and will disappear after successful unlocking

note: symbols are meant to be in circles, brackets are as close as I could do.

I know this is late, but it may help someone again.
Regards
DC

Mr C.
December 2008