I don’t actually think that it is the power supply but its just something to try before disposing of it. If you think about it there is little the average person can do with a faulty player. This suggestion was simply something that came into my mind while I was typing out a reply.
Regarding the power supply, the connector is pretty standard and so is the negative outer, positive inner arrangement. As the player takes less than 12 watts (in fact with my meter nearer 5 watts) he could also get away with a 1 amp supply for testing purposes. If he has any other WD players / hard discs he will probably have a compatable one for test purposes. Given all this I am not saying that it is the supply, in fact I very much doubt it. Its just a ‘straw’ a person can clutch at before giving in and it forms part of basic troubleshooting.
