The bad year was 2008 for Solder balls from H3LL (GPU chips defective)           

Solder balls from H3LL:  by Nvidia, chip errors.
CIRCA 2008.  (newer PCs just ignore this)
lead free year, horrors.  (this horror is a mix of bad design and allowing the PC to overheat) (blame is in Nvidia camp , I guess)
This began with USA government laws, banning lead (Pb) kicked IN and caused the below results,  just like all mandates, things go bad (for someone, even millions of folks) 
Best action by you is scrap the PC, buy a newer PC.  (get a  desktop this time? ) or HP 8540w. Buy something that has  GPU card inside. (buy a desktop and a dirt cheap chrome book for travel)
This is a surface mount device,  and uses solder pad/balls,  I bet moms oven can not fix this failure !!!
 (I will demonstrate this using a better LT PC, one that has  totally modular , VIDEO CARD)
(this can cause a range of wild and crazy symptoms, and for sure  intermittently and screen acts crazy, as the  LT base is flexed.)
One more clue is the rear VGA  jack fails (using an external monitor), too when the PC is flexed,  (GPU failures do that)
 The 2008 era, LT may have the GPU solder ball failures from H3LL problems cause by the USA Federal mandate of lead free solder, laws.{think Monkey wrench effect}  (yup, it was born dead, complex thermodynamic reasons, low melting point solder) 
The are 3 reasons for this failure, 1: not putting a steel stiffener frame on the MOBO, 2: a bad  brand of new Lead free solder, (too low melting point) and at the same time, if lap top vents are blocked you can overheat the GPU easy,
Some solder melts at 136f (58C)  not saying this was used, only saying they used the wrong solder,, my bench solder sn63 melts at 183C (361f)
Some users placed their laptop on a blanket , it overheats and the solder here was damaged. (like a perfect storm of bad, but is now cured by the makers)
Also some GPU chips  overheated fast and easy. (some LT makers just hid the problem by running fans full time or 2 times faster all the time) (preventing many dead displays)
If sitting on a beach at 120F in the shade, and the LT goes dead, are you surprised? Most will overheat like this and worse if the sun lands on the LT.
One LT, if you press hard on the J key  , the  GPU bad solder balls, connect and  the screen wakes up, or goes dead. (yup)
Or,  remove the key board and press on top of the GPU chip now,  does the screen wake up now? BINGO? bad solder joints you HAVE! (kiss off one MOBO) but not mine below, it's an Elitebook.

My GPU unplugs. (GPU means Graphic Processor Unit, or chip)  Yes the chip runs hot, and has heat sinks, as do those fast RAM chips seen here.
The large chip below is it, and will overheat if the heat sink is missing or fell off.  (loose or the thermal compound is cracked)
The other chips are dedicated RAM for the GPU. The RAM chips on mine have heat sink pads. 1mm thick (I reverse engineered them, 2 ways, the pad them self and the gap measured.)As seen here.
Do not let hacks fix your PC or they many make it worse not using proven heat sink compounds or pads, the correct thickness. 
Warning 2,  I see laptops failing for GPU too hot, I then check the heat sink and find that the compound is now hard as dried clue and brittle,  and is now CRACKED from natural LAPTOP flexing.  What ever they used there for compound is NO GOOD. I use this Grease!.

My Graphics screen driver CARD: below:  (HP Elitebook 8540w)  My LT has 3 card options. (speed)
I love only Laptops that have a card that unplugs, (you do get what you pay for here!!). (not only that, but I CAN UPGRADE IT for gaming, or for CAD/CAM or for Video editing extreme. Yes, PCs are versatile.)
Some cards sell for $20 used.  (what a deal and not one has Solderball problems !)
The solder balls (SMD) are under this big green chip below, called the GPU, graphics processor.  (the conditions of assembly here are complex, Re-flow methods in an OVEN)
It runs real hot, the better and faster the chip the more heat it expels (like gaming does),  The balls can not be home repaired,  doing a ball remelt in moms oven is 100% failure event, I can replace my card but most cheap laptop owners the MOBO is bad now.  $150 used part. or more.
This example below never ever fails for solder balls , but the photos of my GPU are very clear, and you can see no human can go under there, and fix bad balls. (only a re-flow oven might but at home , is impossi)
HP 8540w, is the best LT HP ever made, I hoard them.!
Some simple tests for the Screen LCD is simple and gently twist it in an un-natural way, (out of square) if the lines change the LCD is bad, (sure in all cases, re-seat its cable)
The base of any laptop the case can be twisted in the same way to see if the GPU chip is bad,  see if lines change.
One more test:
The test to see if this chip is bad is press on the Keyboard "J" key the chip is below that key, on your LT the pressure point would be different, read the service book to learn the GPU actual location.
I can also remove my keyboard and then press the GPU chip to my hearts content, to see if the screen acts up.  (2008 is the year of horror for said chips) Call the solderballs from hell PC's

A Bad LCD in most cases.  (the screens can crack where you can see easy or on edges no see from outside viewers)
In most cases the LCD array screen is bad. (non 2008 screens)  If you gently twist the frame of the SCREEN and lines get worse or better, bingo for bad LCD.

Google (duckduckgo) what Lines look like,  in all cases bad GPU, bad  LCD SCREEN or bad/loose internal cable to the LDC.

version 1.  12-9-2017