[quote user="hainesi"]The man in my local Panasonic shop (unsurprisingly I suppose!) told me that newer Plasma screens had eradicated the problem of screen burn.
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To a great extent they have, and the Panasonics have a system which reduces contrast after a few minutes in certain circs to reduce the chance of screen burn. As the manual says:
"Contrast is lowered when the following conditions without
any user operation for a few minutes:
? no signal in DVB or AV mode
? selected locked channel
? selected invalid channel
? selected radio channel
? displayed menu"
In other words, typical circumstances where there might be something left static on the screen for an extended period.
However, there's an opinion that screen burn is more likely during the early stages of the screen's life, so a sensible precaution might be to back off on the brightness and contrast - always a good thing, given how 'hot' most sets are configured by default - and avoid the use of any 'dynamic' picture modes, at least in the early days of ownership. IMHO it's worth avoiding the dynamic modes altogether, but that's a personal preference.
I reckon you should stick with these less dynamic settings for the first month to six weeks, given an average of four hours or so of use per day, just to be on the safe side.
That said, I run a (now slightly elderly) Fujitsu 50in plasma at home, which has been in use for at least three years, and I've never had a sniff of screen burn. So I must be doing something right...