As I mentioned before, I bought a new MacBook Pro recently because the BGA (ball grid array) RAM chips on the graphics card of my old laptop partially desoldered themselves. That left me with a few options; throw it away, buy a new graphics card, or have it repaired. Since I would like to sell it, I ruled out option 1, and options 2 and 3 both cost upwards of $250. That left me with fixing it myself.
After having a look online, I found some people who had been successful in fixing their laptops. The BGA chips becoming desoldered is apparently a fairly common problem. In one success story, a guy used a heat gun and recommended that the work be performed outdoors due to the high temperatures. Having a concrete front porch, and it being a still day, I decided to do just that.
I bought a heat gun from Ace Hardware for $24. It has two temperature settings, 345 degrees C (650 degrees F) and 535 degrees C (1000 degrees F). Figuring that solder can melt anywhere between 200 and 450 degrees C, I decided to try on the lowest setting first. Holding the heat gun 2 inches from the first BGA memory chip, I gave it a blast for 30 seconds with a thick cardboard heat shield protecting the surrounding components. After doing all four chips, I tried the board in the laptop, but the problem was still not fixed. 🙁
So, feeling brave, I gave the first chip a blast on the higher setting. After about 15 seconds, my cardboard heat shield caught fire and a strong gust of wind shook my rig (circuit board placed on a metal cookie sheet). It was enough to dislodge some of the surface mount components on the underside of the chip. Not good at all. I moved my rig into the garage and completed the job on the next three chips.
After moving inside, I dug out my soldering iron, with a very clunky tip, and cleaned it the best I could. Somehow, I managed to steady my hand and resolder three resistors and two capacitors, some as small as a poppy seed. I checked the connections with my multimeter, and despite not knowing the resistor values, reading precisely 300 ohms on all of them comforted me.
I powered up my laptop expecting to see white smoke or a blank screen. To my utter disbelief, the damn thing powered on OK! Checking the hardware properties showed my video card was reporting a full 64MB instead of the 32MB before. And, no screen corruption! The big test was playing Half Life 2 though – it ran without a hitch!
So, if you need your laptop fixing, I am not doing that again. Go and find someone else.