Panasonic LCD TX-L37U3B FBr Fluctating Brightness


Standard Member
Santa Claus brought me a PANASONIC TX-L37U3B Software version 1016-10000 from Comet that is exhibiting what I think is FBr.
I notice it on dark pictures only.
I can reproduce the problem easily. It is apparent on all Viewing Modes
Play a DVD (mine M/C is A Panasonic recorder, via Scart) and pause it on the credits where there is black background and a few lines of White text.
Note the text quickly becomes very dull.
Press the TV Menu button to display the menu popup.
Note the text is now bright. (normal).
Press exit and the text reverts to dull.
I see the same effect on DVB HD programs as well.
I rang Comet and they said to ensure C.A.T.S, Vivid Colour and Power save are all OFF.
It made no difference.
Are there any other settings I could try, or do I need technical intervention.
Does anyone else see this?
BTW, I tried the same DVD test on a TX-26LMD70A S/W 5580-10000 but there was no darkening.
Any advice would be appreciated.


Well-known Member
Do you have the latest firmware ? The latest firmware for the GT30s seems to have helped to pretty much eliminate the FBr problem, or at least reduce the effect to an imperceptible level.

Have a read through the owners thread in the plasma section if there is one.


Well-known Member
Sounds like the auto dimming I had on my Panasonic E3 it's used to produce a deeper black and minimise any backlight leakage showing up. It's a feature of the tv and I didn't like it either! If your U3 is the same as the E3 putting the TV into True Cinema/ or games mode picture mode should stop it ?

Paul MC007

Well-known Member
Definitely sounds like local dimming. As previous mentioned, some LCD TV's will do this by default, it is to try and hide any back-light issue's that might become apparent - I hate this mode on TV's (although there is some logic to it of course) so I always turn it off on my Sony set.

I actually had "Floating Blacks" on my Panasonic V20 (the awful set is long gone by the way!) - it meant that everytime the scene switched from dark to light (even on a conversation between two people on different camera angles) about a second after the shot changed, so did the brightness. It was really, really off-putting..

Guess what though..."within spec" (naturally, of course ;)) when I complained to Panasonic and my retailer.

Hence why never EVER again will I buy another Panasonic plasma. In fact, I would never buy Panasonic anything ever again.

I am more than happy with my new Sony NX723 now......... at last I can watch TV without those annoying brightness fluctuations, with no loud buzz, with no posterisation on people's faces, with no screen flicker, with no phosphor trailing, with no 50hz bug, with no dull whites anymore.......the list is endless!!!
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