If you turn it off and unplug it then the cracking sounds continue, who would tell you that a power conditioner is needed?
My advice is to stop listening to that person as they are obviously unaware of how things work.
Call it in, get your transaction number and document your complaint. It could be the prelude to something worse as the mounting of the display could be having an issue.
Do not delay.
I bought my Series 5 550 Sumsung Plasma TV 3 months ago. Everything was fine the 1st two months, the last month I have been dealing with popping and cracking sounds. These sounds are def coming from the back of the tv. It starts almost immediately when turning the tv on. It pops about every 20-40 seconds or so and it never stops no matter how long the tv is on and will continue for about a half hour after tv is off. It's driving me nuts and ruining tv watching. I live in a house built in 1950 and it still has all the original wiring. I've been told possibly I need a power conditioner?? Maybe it has to do with static buildup? The tv was perfect for two months before this and I did not change anything to my setup.
Does anyone have experience with this... what can I do? Thanks ahead of time!