Facing TV Problems? Ask a TV Technician.
Hello and sorry you're having problems. The clicking is caused by the Mainboard causing a faulty turn on command to the power supply board's relay. The Mainboard will ALWAYS appear pristine whether it's working or not - so there's nothing telltale to be found by visually inspecting the board. That said, we diagnose this problem about a dozen times a day, and additionally it was also posted in the Samsung service bulletin regarding this issue (clicking indicates a faulty mainboard - not a capacitor issue on the power board).
In order to fix the set you need to replace the Mainboard. You can find this board by searching the part number stamped on the board itself (Googling or finding used/pulled parts suppliers and using the search function on their site(s)).
Also, finding one available at the link below brand new from Samsung via an eBay seller:
Before you go, PLEASE DO click at least a 3 STAR RATING, at the top of your screen. That is how I am credited for my efforts by the site.
Do you need further assistance with this?
That's bizarre as the Mainboard is the only thing that can cause this. I'm unsure why you didn't post that you had already changed parts in the TV. I will opt out at this point.