Attempting to fix this faulty control circuit board for the daughter of one of my work colleagues this evening. The white switch (S1) to the right of centre, is failing to latch-on. Tried taking it apart, but no luck. Only source I could find with ones that matched it, was in Hong Kong (via Ebay), probably near where this was all made. Replacement on its way, and should be here in a few weeks. Fairly incredible for just over £4... for a dozen of them! Plenty spares, or switches for other projects.