Memoirs of Fls'Zen

Monday, January 30, 2012

Reflowing MacBook Pro Graphics Chip

Today Dawn's MacBook Pro (A1212) LCD started displaying flickering red instead of "black". Basically, instead of black, it displayed a shimmering red. The black also seemed to include dark shades of gray. Not very easy to describe. Unfortunately, I didn't take any good pictures of the bad video or the subsequent repair operations. In any case, I checked an external monitor with it, and it displayed fine there, so it was unlikely that the fault was internal to the Radeon X1600 graphics chip.

The first step I took to resolve the issue was to reseat the video signal cable. I reseated both ends, but to no avail, it was still showing red instead of black.

My next step was to reflow the X1600 chip. Dawn reported that the red show up while she was watching a video, so the failure s obviously heat related. What better way is there to resolve a heat-related signal quality issue than reflow?

I warmed the chip to 200ºC for two minutes, then ramped it up to 275º over the course of the next two minutes. I held the temperature at 275º for three minutes before cooling it back down with a one and a half minute ramp, dropping a few degrees every few seconds. I was pleased to discover upon reassembly that the LCD was receiving the expected video again. Score one for reflow! In case you were curious, I didn't have an adapter for the chip size, so I just used a regular circular nozzle compensated by increasing the air temperature and duration of a normal reflow.

When searching for the problem online, I found a few of people with the same trouble. It happened to one person when they dropped their laptop. Apparently, it knocked out the connector on the logic board enough to cause the issue. Another person had it go red as described and a few months later, it went back to normal. They mentioned that theirs went wrong when it was hot.

Hopefully someone out there finds this useful someday. Please consider reflow before buying a new logic board! You can get a $100 hot air reflow station from SparkFun, so they cost much less than a new logic board, and can be used for other things as well.

PS: The problem basically looks like this, except the red "shimmers" and isn't constant like the picture implies.



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