g what?; there are many G series, please tell what you have there.
the bottom of the laptop has service tag with full model there.
like G61-1234us. ))1234 is a made up # fake, but yours has one.
NO OS stated
, windows what XP, Vista, 7/8/10?
the PC made before 2010 (see why I ask what you own)
has CCFL lamps that all go bad before now mostly.
like ..G60 ,G61, G70
all those have CCFL, up to 2010 and LED back lamps began.
the brightness works only if the HP drivers for you PC are there.
drivers must match
- PC model
- and OS
- and what graphic chip option it had. day 1.
a 3 way match ! or it fails.
the other DIM out deal, is if the PC thinks it lost AC power.
and is running on battery to save battery life (longer)
all do that, every one made unless turned off
here is the test.
take out that old main battery, leave it out, they dont last this long so, out it comes or it will messup an PC.
if the battery shorts it will confuse a laptop big time.
then run on AC power only.
does the screen now go full bright?
in device manager (from control panel)
are all drivers there ok, on that screen?
next time at least tell the service tag information
so the helper can actually help.
we be blind see?