Mac book pro 3.1(early 2008). Black screen

Question

Hello,
My macbook pro was working fine, until suddenly the screen goes all black (But I can notice that the LCD backlight is still on). I also used an external monitor and I can use the machine by having the monitor plugged in and the lid closed.
I searched the net and knew about a NVIDIA BGA failure that affects the computers manufactured in late 2007, early 2008, where mine is included.
If the failure were this BGA defect, I suspect I would get no image at all, even on the external monitor, right ?
Can anyone give me a hint as to what component might be failing here ? As I said I still have the backlight and can use it with an external monitor. I have heard about inverter failures, but don't know what that is. I need to have an idea of how much a possible repair might cost, because since this machine is kind of old, I might just buy another one in a few months.
Regards,
Daniel Santos

Answer 1

Hi, my late 2007 15" mbp just went dark on me. I can ssh into the machine and run the system_profiler command. Get a load of this: my nvidia gpu no longer shows up and instead it reports an onboard intel gpu with 64mb shared memory.
That TS2377 link above indicates that 4 years is the magic number. I bought mine nov 2007 which is obviously more than that. What are my chances that the article is stale and they'll fix my Mac (assuming this really is my issue)?
Here's part of that output:
Graphics/Displays:
    Display:
      Type: GPU
      Bus: Built-In
      VRAM (Total): 64 MB of Shared System Memory
      Vendor: Intel (0x8086)
      Device ID: 0x2a02
      Revision ID: 0x0003
      Kernel Extension Info: No Kext Loaded
Hardware:
    Hardware Overview:
      Model Name: MacBook Pro
      Model Identifier: MacBookPro3,1
      Processor Name: Intel Core 2 Duo
      Processor Speed: 2.2 GHz
      Number of Processors: 1
      Total Number of Cores: 2
      L2 Cache: 4 MB
      Memory: 6 GB
      Bus Speed: 800 MHz