LG 75SM99 Series Owner's Manual page 20

Generated Sound
• "Cracking" noise: A cracking noise that
occurs when watching or turning off the TV
is generated by plastic thermal contraction
due to temperature and humidity. This noise
is common for products where thermal
deformation is required.
• Electrical circuit humming/panel buzzing: A
low level noise is generated from a high-
speed switching circuit, which supplies
a large amount of current to operate a
product. It varies depending on the product.
This generated sound does not affect the
performance and reliability of the product.
• When cleaning the product, be careful
not to allow any liquid or foreign
objects to enter the gap between the
upper, left or right side of the panel
and the guide panel. (Depending on
model)
• Make sure to wring any excess water or
cleaner from the cloth.
• Do not spray water or cleaner directly
onto the TV screen.
• Make sure to spray just enough of
water or cleaner onto a dry cloth to
wipe the screen.
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