# Panasonic Fluctuating Brightness issue on the GT30



## Andre

I have read quite a few forums reference the subject problem and seen an example on youtube. Does anyone know if this has been fixed i.e. TVs produced after such and such a date, or a firmware update. If it hasn't been fixed does anyone know if it will be fixed, or is it just speculation if Panasonic hasn't formally addressed the issue.

I would really like to purchase the 50inch GT30 but I have been told that if the issue presents itself after I have taken possession I can't simply return it to the store I have to go through service, if thats the case I will not buy. I could get a TV without the problem, but I don't feel lucky.


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## mechman

Are you talking about the the rising black levels? I thought they had that situation fixed. You're not buying a used model are you? If you're buying new I wouldn't worry about it.


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## Andre

Its new, however because its a "special order" they don't offer a 30 day return policy. Some of the current GT30 (not all mind you) have the brightness problem. Here is an example from youtube






I have recently read that Panasonic said the TV is supposed to do that BUT its not supposed to be noticeable. I guess I will have to wait a few months for the TV to hit the mainstream market


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## AVoldMan

I have an older Panasonic 42PZ85 plasma HDTV. I do remember that during early user DIY calibration attempts a similar brightness fluctuation occurred for me. I believe it was either the automatic dynamic Contrast Control that was on (that needs to be turned off for a better and more stable overall picture) and/or the Contrast User control was set too high.

Check your settings on these and modify as above.


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## donnymac

This problem is inherent to 2011 Panasonic plasmas(VT/GT/ST). It is being called floating(FBr) brightness on various forums. It is an effect which was engineered into the display. However it was not intended to be so abrupt and obvious. There are varying degrees of this problem. Some do not see it at all. Others see it once in a while and can barely tell it is happening. Yet others see it to such a degree and frequency that they have returned their sets.
Panasonic is supposedly researching this problem. My personal opinion is that unless it can be fixed with a FW update it will be called a feature just as the rising blacks and floating blacks of previous years were.


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## AVoldMan

donnymac said:


> This problem is inherent to 2011 Panasonic plasmas(VT/GT/ST). It is being called floating(FBr) brightness on various forums. ...
> 
> ... My personal opinion is that unless it can be fixed with a FW update it will be called a feature just as the rising blacks and floating blacks of previous years were.


Do any User control settings help minimize the effect? I know the C.A.T.S (auto contrast adjust) messed up my picture when scenes changed from bright to dark and back. I just turned it OFF - permanently.

I have noticed the rising black levels even on my older Panasonic PZ85. I thought I was seeing things. So I had a colorimeter and measured the black level light output and compared it to older calibration files that I had saved. Sure enough it had almost doubled after about a year of use.


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## donnymac

AVoldMan said:


> Do any User control settings help minimize the effect? I know the C.A.T.S (auto contrast adjust) messed up my picture when scenes changed from bright to dark and back. I just turned it OFF - permanently.
> 
> I have noticed the rising black levels even on my older Panasonic PZ85. I thought I was seeing things. So I had a colorimeter and measured the black level light output and compared it to older calibration files that I had saved. Sure enough it had almost doubled after about a year of use.


From what I have been reading from owners and DIY calibrators keeping contrast low helps a lot as does calibration. They are also experiencing the same problem with this years Samsung plasmas. It seems not to be as bad or as common as on the Panasonics.
I have a 2009 Panny 05V10 and my black levels have tripled. According to Panasonic this event was "as designed" and therefore a feature.


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