Going back to the original thread question, I think that experience suggests that if a product doesn't work right brand new, you are better taking it back and getting your money back/switching to a different product. I think often that if something doesn't work on a new purchase then the whole batch is likely to be wrong. I had a new amplifier that hummed, the replacement did as well. I had a tuner that had periodic signal drop out, found on the internet it was a persistent problem with that model, got my money back. A replacement cd player on a warranty has a periodic grating sound when loading and is slow to load, this is a common theme for the model on internet reviews. I guess the approach of just killing the deal straight away is a bit brutal, but I think I've come to the view it saves a lot of hassle in the long run.