HP DV6000, help needed, I am out of ideas

Here is my huge problem, I have an old dv6000 with t7200 cpu and nVidia 7400m, a month a go it stoped working with a black screen (I know what you think, the GPU died, I thought that too, but as you will see that was not the case) so I did some research and all was pointing to the well known issue with the gpu possibly overheating and finally dying.
So I got a brand new motherboard(not used, brand new from HP) put It all together but again, no go...
Next, I thought it might be the CPU, so I replaced this as well...again no go!
After starting the computer the screen still stays dark, all the lights come one, the fan spins, but that is it. I tried to plug it to the external monitor, same result, no output, screen stayed black.
At this point I am out of ideas, can you guys please help, any ideas are welcomed.

 

Did you try inspecting the LCD cable? This is usually the first thing to break from being moved constantly when closing lid. If not that maybe LCD? I take it there is no sound working either?

Usually you need to tell the laptop to use the external display. Maybe it needs the built in LCD to select duplication.

Tried any other memory? Removing non-essential hardware? cd-rom, etc..

None of that works, I'd exchange MB with new one again, to rule it out.

I'm sure you know all this already but I'll try.

What is the model # out of curiosity?

 

Thanks, but tried all that, this is the second MB I am trying and I tried 2 other processors.
Yes, there is no sound, and both screens stay black, only the lights on the base come one and the fan spins, also the HDD is working.
model is DV6000CTO.

 

Bummer....

My first thought was power supply... But you surely tried another adaptor...
Must be a short somewhere. inspect carefully???

 

That is what I am thinking as well, probably the power inverter board, because neither on battery or external is working.

 

I still face the same issue guys, even after I replaced the power inverter board, is there anyone with similar problem that can help, it will be highly appreciated.

 

IF you have replaced all of that and its still not working, i dont really know what else could be wrong...
I had something like this happen to one of mine and i still have no idea what was wrong with it.

 

Start here and work forwards or backwards or what ever sounds like your "shotgunning" your problem throw enough dookie on the wall some is bound to stick. Start here. Troubleshooting LED Blink Codes or Beep Codes During Startup or Boot HP Pavilion dv5000 Notebook PC series - HP Customer Care (United States - English) Post up with what you find.

 

Try testing with a PCI POST card.

 

Try hitting FN+F4 to cycle between internal display and external.

Also, have you replaced the display cable? Part number: 431394-001

On page 5-35 of the service manual, it shows the location of the display cable.


Service Manual: http://h10032.www1.hp.com/ctg/Manual/c01035677.pdf

 

Nope, the display cable and the switch cover are the only things I have not replaced so far, I am going to try with another laptop that friend of mine has and see if that might be the reason. Its just so weird, I've never seen such a thing, and I have repaired a lot of laptops, cell phones and other hardware in the last 15 years, this one just killed me...
Oh, and there is no beeps or blinks, all the lights are on, I can hear the fan, the HDD and the CD.

 

You might already tried it but I have weird similar issue. The ram in my laptop suddently won't work together(identical). Both tested fine singly and on both socket. Once I put a non-identical chip on it works.

Boots up like GPU issue, but not. I've seen this on 2 of my DV4.

 

I tried taking the RAM out, and than turning it on, which should work at least to boot to POST/BIOS, but that did not work ether.