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Old March 22nd, 2012, 12:46 AM
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Jintan Jintan is offline
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Join Date: Dec 2004
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Had a bit of luck with one of these today. Had been reading online about various techniques that have worked for some. Re-seating the gpu really requires some type of BGA reflow/rework station, starting usually at around $1500 USD (likely one about $2300 is what is really needed). But kept seeing mentions of using a heat gun, melt solder on a US quarter coin, mark scratches in it (so you can verify when the temp melts solder), then heat the solder on the coin till it melts, which then reseats the gpu to the board.

Fortunately I had a few dead boards to practice techniques on, and get any mistakes out of the way. Including using a cardboard square tube placed over the gpu, and hold it with an oven mitt, since the temp is about 850 degrees F. Hard to get a light on the solder to see it melt, and was concentrating on that so much, I didn't notice that the oven mitt and cardboard had started to burn until the smoke hit me.

Ended up using bondo fiberglass mesh to protect the other board components.



Cut correct-sized squares through a few sheets of it, placed some thermal paste sparingly around the first sheet's hole, to sorta hold it in place on the board, melted about a foot of 60/40 solder onto a quarter, then thermal pasted that to the gpu. Cut some cross-hatched scratches into the solder (a visual to tell you when the solder melts - ie. also the solder under the gpu).

Need to remove any of those black tape pieces nearby they place on these boards (usually sticky enough to put them back later, if you're careful taking them off), or they'll fry. Most of the circuitry around the gpu is surface soldered mini-resistors. The solder on them may also melt a little, but as long as they are undisturbed, they'll just stay put once the heat is removed. Probably a biggy just to make sure no movement occurs until the heat is removed.

Heat gun at high, solder shined bright when it finally melted, gave it a few extra seconds because the gpu solder is lead free, so needs a higher melting temp.

Put the laptop back together, and, son of a gun, it booted normally. Ran it about 5 hours after while the battery recharged, and give it another long test run tomorrow to see if it still will just fail again.

Last edited by Jintan; March 22nd, 2012 at 12:59 AM.