Laptop HP Pavillion dv6500

gregrocker said:

When you say it turns on and off repeatedly it implies you are seeing something on the screen. Is there any signal at all, like the HP logo which could mean it will operate in boot mode?

Do you get any signal when you plug in an external monitor to the VGA port on laptop?

If so it could be the monitor has come unplugged internally. Videos on the web show how to check this for your model.

Nope I know its turning on cuz of the led lights all turn on when pressing power on but it only last 2 seconds and then off.

2 second is not enough time to show anything on the screen so its totally black.

1-2 leds on, 1-2 leds off, 1-2 leds on, 1-2 led lights off. .. .. .. .. .. .. .. .. .. .. .. and so on.

What about the external monitor. That will tell you if its the laptop screen.

Its HP DV 6500 so I bet that its GPU problem (90%) you need to re-solder it.
How to do reflow re soldering. That's is a different question. It depends on what can you do.
Can you assemble/disassemble laptop computer? Do you have hot air station/infrared station/heat gun/oven?
search youtube.com for videos with explanations
for example this person made video how to do it with oven (not the best thing but because many people have them at home it's most accessible)
HP DV6000 Motherboard Reflow - YouTube
it has same symptoms on LED light turns on and off.
I have fixed HP DV 6000 series laptops with same symptoms.. In my experience it was 99% GPU solder problem. sometimes if you've very bad luck GPU chip is damaged too. HP engineering is to blame here cooling system design was flawed in DV6000 series DV9000 series and some other HP laptops. They all failed because of this sooner or later. search with google.com and you will see. Right now I'm getting ready to repair yet another HP DV6000 laptop with this problem.. its my free time thing so.

by the way I take no responsibility for your laptop you should know that you can do more damage to your laptop if something goes wrong.

So perhaps he should plug in a VGA monitor to see if it is the GPU first?

gregrocker said:

So perhaps he should plug in a VGA monitor to see if it is the GPU first?

That's of course good idea, but as I understand by reading posts his laptop would not stay on more than 2 seconds it turns on (blank screen only power etc. LEDS light up) stays on for 2 sec then off for 2 sec and on 2sec and cycles that way.