I baked a computer (and it worked!)

This weekend a friend asked me to have a look at his HP DV9500 laptop.  It was having trouble - when you turned it on, the screen showed nothing but a solid grey with a few thin black bars.  The grey increased in intensity as the system ran, until it ran off the colors that the display knew how to show.

Clearly, there was a problem with the video card.

I tried plugging it into an external monitor, and lo and behold, the system was actually booting fine!  Just the video card had lost the ability to send a coherent signal to the built-in screen.  I thought this might be a problem with the connection inside the laptop body, but then my friend explained what HP had told him.

This was a factory defect.  DV9500 laptops that shipped with the NVIDIA 8600GS video card tend to run into the mysterious "grey screen with black bars" problem about 2 years in.  Oddly enough, 2 years is the limit on the standard HP warranty.  People within warranty have the laptop replaced for free.  For people outside of warranty, it costs 570€.  My friend was in the latter, SOL category.

So I looked into the problem a little bit deeper. According to my google search, the problem is actually that the solder joints between the GPU and the motherboard use a kind of solder that doesn't stand up to high temperatures very well.  High temperatures like those that might be generated in a compact body laptop with a powerful GPU in it!  The solder balls up or cracks, making the GPU prone to failure.  So to fix the problem all you have to do is re-solder all the connections between the GPU and the motherboard, ideally using a kind of solder that handles high temperatures better or forcing the GPU fan to run faster.  Easy, right?   Hahahahaha no.

One forum user suggested a solution, I think in jest: just put the motherboard in the oven!  The heat will melt the solder, and it will fill in any cracks.  But people tried it, and reported that it worked for them.  So with nothing to lose, we tried the same.

Easier said than done - of all the laptops I've disassembled, the DV9500 has got to be the worst.  22 screws for the underside exterior alone, and 3 more layers to get through after that!  Probably about 75 screws to keep track of in the end.  Plus you have to peel off all the anti-static plastic they've got glued to the motherboard, and remember where all THAT goes... I found this disassembly video for a similar model to be very helpful in reminding me where all the screws and plastic went when it came time to piece it back together.

Here are your steps to baking a repaired HP DV9500/NVIDIA 8600GS:

1. Get the motherboard out of the case.  We want just the motherboard, with no plastic, screws, or additional parts. This is a pain in the ass.  As you remove the screws, lay them out on a flat surface in some semblance of their layout on the actual laptop.  Don't be afraid to a map for each layer - there are a LOT of screws on this guy, and you don't want to forget what goes where! 
2. Pre-heat your oven to 175-200 degrees Celsius (350-390 degrees Fahrenheit).
3. Ball up 4 pieces of tin foil into cone shapes, and place them on a baking sheet.  Place the pointy end of the cones on screw points on the motherboard.  This is because screw points are lined and electrically insulated from the rest of the mobo - we don't want any solder dripping down!
4. Put the motherboard in the oven for 6-8 minutes. Set a timer.  You will smell burning plastic after about 3 minutes - don't worry.
5. Remove the motherboard, and set it out to cool for 30 minutes.  I put mine outside in the winter air for 10 minutes, same effect. :)
6. Piece your laptop back together, and hope!