pavilion dv4 1120us won't boot

[econ4caster]

My pavilion dv4 1120us control panel lights up when started, fan comes on and clicking is heard for about 3 seconds then nothing happens--no screen (remains black) and no further evidence of booting (no sound from the hard drive) but the lights stay on.  This happened after the battery was severely discharged because the charger plug was not making good contact. I took it to a Best Buy diagnostic desk but they can get a diagnosis without a boot up and an active screen.  It happened once before under warrantee, I sent it to HP for work with a problem description, and they sent it back saying they could not replicate the problem and it was working fine.  Any ideas on where to start?

[Al2]

Have you tried a hard reset?

Continuous LED glow in the table of blinking codes seems to mean "The AC adapter is attached and the battery is charging, but does not yet have sufficient charge to power the notebook."  Could you give it a try with only the AC adapter, after having removed the battery? The power adapter alone should be able to power the laptop.  If still not working, the AC adapter may gave gone bad and unable to provide the required current.  Swapping with another similar adapter may help narrowing the issue down.  

[econ4caster]

I did try a hard reset to no avail.  I also removed and reset the memory chips in case they had somehow lost contact.  I get a led light code of 4 blinks which translates to a video card issue, but I don't know how to pursue and repair that.

[Al2]

Is the system still covered by warranty?  If not, your options are either to send it off to a laptop repair place, replace the main board yourself, or attempt a heat gun resoldering of the GPU outlined in the following four posts: [1][2][3][4].  The service and maintenance manual should help with disassembling the machine to gain access to the main board.  

[niksona]

Hey, I have the exact same problem and wondering if you got any resolution to your issue. Please share. Thanks.