I was supergluing a cracked corner of a case... the superglue was sitting on the case for about 30 secs when I wiped the excess glue off and noticed brightening. I made a test 'J' next to it, waited 30 secs, wiped it off... Hmm...
after much messing about I mostly succeeded in performing a polarizer replacement on this 2400c panel
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the soap method @jmacz mentioned was indispensable... highly advise removing the backlight first though...not perfect, but sure beats a crackled smelly vinegar panel