HISTORY and specific HP only models of PC that love to fail for bad LCD  CCFL tubes:
Most of these PCs died 5 years ago from these short lived, CCLF back lamp tubes.

THEN CAME WHAT? "LED back lamps came later" 
The bright white LED was introduced in September 2003 by Cree, but it took many years  for PC makers to latch on too this device. (slow my guess, is was  due to LED costs in 2003 ,or near)$2 a pop is super expensive.
CCFL's ended about 2010 in Displays.(LED takeover) Just as CRTs died down fast, and for sure helped with the push over.
These tube lamps can fail dead, or go dim or go yellow or flicker or the inverter power supply for it is bad. (some PCs have many tubes and only some die making a huge BLACK BAR)
Do not forget that many old CCFL laptops you can buy a LED conversion  upgrade for many, as seen in ebay...(For HP621 / G60 / DV6 / CQ60, and more )

This HP only ,  table is not complete: (one trick is to pretend to buy a CCFL for you screen, if can't? then it has none.) Trick 2 is to read the service manual, see words toxic for Hg Mercury , bingo CCLF.
Old Laptops. CCFL Most PCs (and monitors) changed to LED in 2010. (large screens then small)
Most old  Compaq CQ series , CQ40,50 ,60 61,62 all made before year 2010.
Compaq 6500 to  8700's  , and 2000, 2500
G3000 series
NC4200 to, NC8400 
NW8400 to NW9000 series
NX6000 up to nx9100 series.
TC1000 and L2000
Compaq 500-550  hp 500 series , 1800 series
DV1000 up to  DV9000 series.
ZX5000 series  , ZD8000
V1000, V1100
ZE2000  to 5000
all old DV4,5,6,7,8, series. (as in dv4-1234us) on up.
and lots more..G60 ,G61, G70
Very old Elitebooks had CCFL 6530s,6930s,8510,8530, 8730.
 (never 8540s) (oddly my 8540p/w  are both LED)
I think Elitebook codes, are  xx30 and xx10 means CCLF inside.. on Elitebooks.?(a theory
Monitors only: with CCFL , and internal HV power board. (seen here with HV jacks!)
L15xx series,  L1503 is common (the first 2 numbers are size wide)
L17xx series  (see image link  just above called HV)
vs17, vs19. VS15 bit VS19 is LED.
and more. 
but a warning; I saw some old names like L- Series,a monitor with LED the last year it was made and  a new power board inside to match.
The introduction of LED started with large screens at and above 20" , then moved to more narrow screens later .(cheaper screens last).
Here is another cool list ripped from the heart of Fleabay (random sellers)

530 550 6700 6710b 6710s 6715b 6715s 6720s 6730b 6730s 6735b 6735s 8500 8510p 8510w

EliteBook 8530p/w

G3000 G3100 G5000 G50-100 G50-200 G6000 G7000 nc8230 nc8400 nc8420 nc8430 nw8240 nw8430 nw8440 nx7000 nx7010 nx7200 nx7300 nx7400 nx8220 nx8410 nx8420 nx9100 nx9105 nx9110


 dv4000  dv4100  dv4200  dv4300  dv4400  dv5000  dv5100  dv5-1000  dv5-1100  dv5-1200  dv5-1300  dv5200  dv5t  dv5z  dv6000  dv6100  dv6200  dv6300  dv6400  dv6500  dv6600  dv6700  dv6800  dv6900  dx6500  dx6600  zt3000  zt3100  zt3200  zt3300  zt3400  zv5000  zv5000t  zv5000z  zv5100  zv5200  zv5300  zv5400  zv6000  zv6100  zv6200  zv6300  zx5000  zx5100  zx5200  zx5300


 C300  C500  C700  CQ50-100  F500  F700  R3000  R3100  R3200  R3300  R3400  R4000  R4100  V4000  V4100  V4200  V4300  V4400  V5000  V5100  V5200  V5300  V6000  V6100  V6200  V6300  V6400  V6500  V6600  V6700  V6800  X1000  X1100  X1200  X1300  X1400

end CCFL, avoid all PCs with CCFL.

The old monitors (etc) don't tell you its CCFL or LED, as LED not invented yet, (bright white LEDs for display) so the never even say CCFL.
The newer books for newer displays, with LED ,flat out say in the spec. it is LED backlighted.

version 1.  12-9-2017   ( if you love your PC?, Laptop , use an  external VGA monitor for the remainder of its life)