It always clicks and switches off the display output to TV when doing an update. As long as the front panel is showing the progress. Just wait until the progress gets to 100% and complete the update.Well I've got a 3500 and mines doing the exact same thing. It usually keeps the front display panel on showing the progress, but it's just switching off. The only way I got it back on was through switching it off at the mains, which I really don't like doing when doing firmware updates.