Mick - you're a genius! I had this problem ...
I set my Beko to do a 90 degree wash and after a while noticed that the prewash light started flashing (think it happened between end of wash and beginning of rinse cycle).
Found various postings which said that it was the childlock and advised pressing 2nd and 4th buttons for 3 seconds to reset. Obviously this failed because it was not a childlock problem.
Some other posting said that they cleared the flashing prewash light by powering off and holding in the play/pause button whilst turning on again. This stops the prewash light but (as stated in the posting) makes the Play light flash! I then just kept pressing Play and it ran through functions such as fill, tumble, rinse, spin a step at a time. Very tedious and obviously not long-term but enough to get me out of a predicament of not having my stuff washed. Eventually even this would not work.
I then found postings about blocked filters and so opened the little pipe at the bottom right (front) of the machine. Water poured out (and little girls' jewellery and some pennies!). I cleared this up but was back to my flashing prewash light!!
And then I found your posting and tried it. Success! It is going through some rinses now and appears to be OK again.
Is this issue only for Beko's or do other brands have the same problem?
Maria, September 2006