Nov 2013: Update:
2nd logic board bake yesterday. It worked!
Following the first bake in July, the problem resurfaced after about a month.
I did not get a chance until now (Nov) to perform a rebake. ( It can be done multiple times.)
It was a lot easier to go through the process a second time, and much faster.
This time I paid close attention to the finicky cleaning and application of the Arctic Silver to the processors. Drawing the heat from the processors is critical, it seems, and by all accounts it is worth the effort.
July 2013: A few weeks ago my old Macbook Pro suddenly started flashing strobe-like and then froze. Very suddenly. A reboot, nothing. Halfway through the boot attempt a tinted curtain slowly descended, as of on a stage, with a message in three or four languages to reboot. This kept up, so after pulling the files off by booting as an external hard drive, I took it to Apple. Their diagnostics showed broken communication with the Invidia chip. The computer fell off the edge of Apple-repairable because it is more than 5 yrs old. It is now "vintage"(it feels like only yesterday). After a visit to a secondary establishment who talked up a whole bag of ozone-producing hot air I went online to any forums I could find on the subject before I offloaded it for parts.
There is a lot of info about this Invidia problem with older MBPs posted all over the place. This chip is in many gaming systems so there are plenty of vested individuals identifying the problem along with posting details of solutions and follow-ups, as well, which is good.
I followed the instructions step by step for taking apart the mac. Here is that info.
One thing that helped keep order in the process was to employ some regular adhesive tape turned sticky side up, secured with more tape attached to its edges, and set each tiny screw head-side down in the pattern of their location in the computer.
Above is from the interior of the computer; all the screws on the logic board and the fans and the optical drive, which must be removed.
Then I watched this VIDEO to get a handle on what I was about to do:
this is the underside of the top keyboard part with optical drive removed and perched there upper left and the two chips of ram removed and sitting on the lower right. The brownish ribbon thing has a 'snap' connector which needs to be carefully popped from the logic board as keyboard top is removed.
strips of tape secure the fans, (see right side fan flipped up on its tape) which i peeled back to pull them out entirely. using a small artist's paintbrush I swept the fans while holding it near the nozzle of the house vacuum cleaner. (nylon-stocking mesh over tip prevents important parts from shooting down the hose and co-mingling with revolting stuff you don't want to stick your hand in). ditto the rest of the interior of the computer, which collects a lot of dust over time and inhibits the effectiveness of the fans, I read.
BOARD UNDERSIDE VIEW
In the middle of the logic board you can see the three big main chips with gray splodges of thermal compound on them. This compound provides conduction between the chip and the heat sink bar thing on the floor of the mac, which is in turn connected to the fans. The fans connect to sensors on the board, so they know to turn on when things heat up.
Video makes things run really hot, so, I guess if any of these links are weak the system encounters problems.
When replacing the board after the bake it is important to replace every connection again. There are twelve in all. (on mine. Not sure if that differs from year models up or down.)
The following BLOG by Russel Heistuman I found very helpful.
Not only are the details on the problem and procedure clearly laid out, the author follows up regularly (he baked his 6 times!). Here is his BAKE procedure. It is worth spending time reading all the comments, too, as there is a lot to be gleaned from them.
One important thing is the thermal compound. It is important to:
AFTER BAKE: apply 'surfectant' (however the hell you spell it) which enhances the conducive properties of the newly applied fresh compound - a one-inch line oozed onto the chips, before reassembling the computer.
I found an equivalent Arctic 5 thermal compound kit at radio shack and the Torx 6 and Phillips #00 at Sears (which sells them individually)
BOARD TOP VIEW
In addition to the dozen or so screws which are removed, there are also some foam buffer pieces sitting on top the usb ports, as well as two plastic gripper/washer type things at the rear edge of the board which pull off easily - if they haven't already fallen off during the extraction. In short; anything that is likely to melt in the oven should be pulled off.
The RAM had already been removed (this is pulled following the battery removal at start).
Line a baking sheet with aluminum foil and roll additional pieces of foil into four balls. The board will sit up on these raising it a couple of inches. Helps to get even heat all round I suppose.
Preheat oven to 375 F and place board-on-baking sheet inside for 7.5 mins (if in any doubt about oven's ability to reflect accurate temp, procure a separate thermometer to sit inside so you can verify).
Remove and allow to cool for about 20 mins.
Reassemble board into computer simply following backwards along all steps. At this point you will be uber glad you laid all the screws out on a "map". Ha!
Presto!.... and 5 days later is still going fine. Better in fact.....
This is good. It means all the parts are talking to each other. So far all the ports are working fine, too. What's interesting is that the fans are not cranking up to high speed so often as they used to, so i imagine that has to do with the improved communications and heat draw-off via thermal compound.
