SamyGO

I think 3002.1 could be downgraded too, master juuso will told about it. I want to talk about why your TV became normal with game mode.

Game mode is invented due reduce input lag from ~300 ms to ~100ms. In this mode, TV discards some video filtering algorithms.
I believe your TV has some defect on those filtering chips. Enabling game mode disables those chips and your TV works normal.
From this approach, your TV can't be fixed by FW upgrade or downgrade. It's also logical that if this error due firmware, why other 3001.1 doesn't suffer from this?
It might be solved with upgrade but I think there is too little chance.

If your fw is T-CHU7DEUC, then your TV is CI (non plus) and you always can downgrade firmware with FFB tool. Sure, just if copy to TV function isn`t disabled.

But i believe, your problem isn`t related with firmware version, i completely agree with Erdem, it might be hardware fault. So upgrading/downgrading firmware probably does not remove flicker.

erdem_ua wrote:... master juuso will told about it...

yes it works i downgrade my tv after repair form 3000.1 to 2005.1 (Advenced Modifaced)

tengle wrote:I will upgrade to 3002.1, get proof that it doesn't help, get the TV repaired and then downgrade

I like your point of view

tengle wrote:Update: Of course the fw upgrade didn't fix the problem

Amazing... Why samsung does recomend fw upgrade they stopped to support 2009 y models for a while. Any respect to customer