No display backlight, no warranty, left IO board to blame, options?
I have a Macbook Pro (15", 2008, A1260) that a few weeks ago started showing lines all through the screen. I figured it was nVidia GPU rot, so I sent it off to Apple for free out of warranty replacement of the logic board.
When I got it back from my local Apple Store, the tech informed me that they were "unable to fix the display issues". They gave me back my Macbook with a nice new logic board, complete with a nice line-free image on the display... and no backlight! Come on, that was never the issue, my backlight was always fine!
Well, now Apple refuses to troubleshoot or fix the issue that came up while the machine was in their care unless I pay them over $300. I'm not putting that in to an old machine, so it's left to me.
The first thing I tried was replacing display's LED driver board using the instructions here. Nothing, no backlight. I replaced the whole display with a working unit from another Macbook Pro and that display didn't light up either! I switched back the displays.
Next, I took the left IO board from the working Macbook and placed it in mine. Success! My display lit up! So now I know the issue is somewhere on my left IO board. Nothing happened to it, no liquid spill, no drop. It just broke when I sent it off to Apple to get fixed.
I'm an engineer with experience soldering surface mount components. All the other features on the left IO board seem to be working just fine. Short of replacing the whole board for over a hundred bucks, if there anything I can look at replacing (or shorting if it's unimportant)? Or should I just cut my losses and grab the board I need? Or do I have more power to force Apple to do this for free than I imagine?
This is highly unusual behavior for Apple. I've never had anything but perfect service above and beyond what was expected even to the extent of replacing a cracked $100 + screen frame on an Nvidia issue. The only time I've ever a had a problem is when dealing with an Authorized Service Provider - who are not actual Apple people but hold a license to do repair work for them. Did you contact Apple first on this or just send it in? You did get a free logic board (about $700), and we've heard from others that Apple is closing out the Nvidia free repairs as the class action law suit settled last December. You might be able to go up the chain of command and get it replaced or just count yourself very lucky on the free logic board, bite the bullet and pay $120 for a replacement I/O board.
I would contact Apple Customer Relations and tell them that during the repair of the motherboard for the nVidia GPU issue, that the tech damaged the left IO board and they didn't replace it.
As for if there is something that can be replaced or resoldered in place, i don't know the part enough to tell you. Somebody else here will be able to tell you exactly what part on the left IO board to look at. Personally, I would just replace the left IO board as you will at least know that it will work as you have already tested that way.
If you short the fuse, you will create a fire. If you are actually an engineer, you should know better than to suggest this. Shorting fuses used to be something that you would never do under any circumstances. I see at least 3 boards per week where people tried to short fuses and it failed. I see many where they did successfully without causing fires. Please don't do this.
Replace that component. You should be just fine.
edit, I did not see your response where you stated you've already found F9800.
There are two ICs on the main logic board that control the backlight voltage for the left I/O board, a driver chip on the left I/O board next to F9800, and a fuse.
Can you please let us know which exactly was bad on your model?
Lastly, sometimes these fuses blow but still show continuity on some meters because it is not fully disconnected, just high impedance. I see this happen often. It could not be fully blown.