How can i unlock my Philips TV?

I have a Philips 21PT4456/05 which i've had for years with no problems.
Switched it on today and had picture for 10 minutes, then screen went black with the word "sparrad" appearing in red in the middle of the screen. Unfortunatley the remote has packed in, but the volume, menu, channel buttons on the tv will not do anything to stop the message.
Apparentely sparrad means LOCKED. This has never happened in the years i've had it. Can anyone help, at a total lost.
Thanks