True, this tactic also worked for me when fighting ebuyer over a defective laptop. It's all in the public domain.

Hello Sean, Hope you read this! I felt compelled to reply as my TV is also faulty, 15 months old, and from Dixons! I have just sent my tv to them and have let them carry out a report without having my own done first. I thought I would put my trust in them. The good news is they have found a defect, are replacing the screen, and refunding me my £95....however...it wasn't easy! My tv had a really feint line down the middle of the screen which they claimed their engineers couldn't see. So I had a phonecall telling me that there was nothing wrong with the TV and that they would be returning it and my £95 was down the drain. I refuted this and sent them picture evidence of the line, and insisted the engineers take a closer look. I got my way and they saw the line in the end. It took many emails, phonecalls, and bombarding their facebook over the course of a few days but it was worth it. Your problem certainly sounds easier to spot than mine though. So I would go for it and get them to do the report. I suggest taking a video of the fault before you send it off. To summarise though, I found their customer service was (mostly) helpful. It wasn't their fault the engineer had rubbish eyes. Good luck with it.