probably just a faulty digital clock display (it happens)if you take a close look at the diplay window you can sometimes see 3 very fine wire lines that run across the front of the display (horizontal)
if any of these are broken then it is defo a knackered clock .
expect to pay £100 + for the clock itself without labour .
clocks are always the most expensive individual parts on cookers
maddogmadox the cooker engineer, September 2007