Xbox 360 BGA Reflow Tutorial.
This is the profile for reflowing the CPU and GPU:
Items Required: Aoyue 968 Repairing System, Air Nozzle Y3939, Air Nozzle Y4141, Rosin Flux Liquid (Must be Lead Free), Walmart Presto Griddle, Custom made stand for air flow device, and Squirt bottle for liquid flux.
Step One: Use squirt bottle with small nozzle to insert flux between BGA and board. Make sure board is on its side in a vertical position. You want flux to ooze out the bottom of the BGA. Rotate the board until flux is coming out of all 4 corners to be sure of an even coverage of flux. (This is optional, we do NOT do this step.)
Step Two: Preheat griddle to 350F. Be sure the motherboard is raised ¾ of an inch off of the griddle. Use JB weld, washers, and machine screws to achieve this. Allow the board to preheat for 5 mins. Heat the board itself for 5 mins.
Step Three: Use makeshift stand to hold air gun. You do not want to hold it by hand because the chip needs even coverage of heat profile for 5 total mins. Place gun and proper nozzle over the chip you wish to repair. Set the Air flow system to its lowest heat setting at 90C for one min. You want an air flow setting of 5. Any higher will result in the air flow blowing important parts off of the board.
Step Four: Turn Air flow machine up to 195C (This will make the flux boil) for one min.
Step Five: Turn off the Griddle.
Step Six: Step up temperature on air flow 3C every one second until the unit reaches 350C/360C. (The temperature at which solder reflows) Hold at 350C for 10 seconds for CPU, hold at 360C for 15 seconds for GPU.
Step Seven: Step down temperature on air flow 3C every one second until the unit reaches back to 290C.
Step Eight: Drop temperature to 90C as fast as the machine will allow. Turn off machine and DO NOT disturb the board for 15 mins while the solder hardens.