you did all that but the acid test.
does it fail on ANOTHER PC<
if yes,them monitor is bad.
all do that, LP2465, all do.
if the monitor passes the acid test.
then the 2nd port on this PC unstated is bad, on the unstated video card. or its drivers bad. or OS corruption.
im sure you moved the dvi cable left and right on video cards
to see if the video jack was it.? right?>
the monitor has 2 DVI ports, try both?(it auto switches inside)
this monitor is 10 years old, 2007 (oldest) carbon14 dated.
as such back then, we did not have LED screens yet.
History matters.! in all cases. of electronics.
until 2010 but some did just before only the top models big.
i read your users guide, the 2 clue2 there, are
"this extends the life of the back lamps"
ahh but page 41..... is better.
http://h10032.www1.hp.com/ctg/Manual/c01446650
the tubes have Hg. mercury inside, BINGO FOR CCFL for sure.
CCFL all do this.
goes yellow
goes dead
goes, dime
goes blinking or completely intermittant.
all do that, even in 2 years, in presentation mode, (on all the time)
CCLF BLACK LAMPS ALL DO THAT
and lasting, 10 year is , kiss the tooth fairy moment,
looked in the HP parts surfer, no parts in stock related
the monitor dead is worth $20 used.
so if it really is bad, then fixing it would cost 2 times
a new monitor, $75 new.
I could not find parts for yours, anywhere, see what LCD is actually there was not easy to discover.
2010 is the end if CCLF, is all I know, unless parts support exists.
https://www.walmart.com/search/?cat_id=0&facet=screen_size_monitor%3A24%22+-+25%22&query=computer+monitor&sort=price_low#searchProductResult
