The repair never worked

@sayabo "I did the yellow light of death repair." does not tell us how you did it. If you used a hot air station it will be difficult since it gives you the temp at the nozzle but not at the chip. Even worse would be a heatgun without any temp control. So, poor control would be the outcome. Problem with such hot air stations is that you can't evenly heat up a large area. The outcome would be that you are burning one area, while the solder has not yet melted on another. You might also run into the board warping since you do not have a preheater. There are large IR with preheaters and tight temperature control for this. What you are really looking for is something like this. It provides the proper preheating and you can control the heat to the IC and limit it to the IC. Even tho there are no real alternatives to using the right equipment, if you were using the station (or a heatgun)you could consider adding something like this and using a thermometer with thermocoupler like this. Use a griddle as preheater.

Again, really not advisable but if it is the only option you have then you can consider it. Chances are minute to get it done properly.

Now with all this said, you do need to remember that this is not always a failure of the solder balls which connect the Flip Chip BGA package to the motherboard. It does happen and you can see why on here More commonly however is that the failure is due to the chip design itself.

As you can see the "bumps' are what actually connects the die to the substrate to make the chip complete. If these bumps fail the die does no longer make contact with the substrate and thus no contact with the circuit board. The chip has failed.

Here you can see the space where the bump has failed and no longer makes contact. We are talking microns of space here. So a bit of pressure on the top of the die potentially close the gap. Same with a reflow, it may allow some of material from the bump to reshape and starting to make contact again. The heating of / cooling of the chip during use is what will eventually cause it to fail again.The proper definition of that can be found at Wikipedia "is a method for interconnecting semiconductor devices, such as IC chips and microelectromechanical systems (MEMS), to external circuitry with solder bumps that have been deposited onto the chip pads." So what happens is that the chip heats up (due to poor design of the ventilation and heatsinks of the console. Does not matter if it is a PS3, a XBox or some of the Mac laptop's) and the bumps that connect the chip to the substrate lose contact and your chip (in this case processsor) fails. The heating of the chip for the reflow actually reshapes (most of the time) the bumps to the point of making contact again. That is the reason why some reflows just do not work. The connection between the IC and the substrate has absolutely failed. In those cases you will need a new processor. Not the most scientific explanation but I hope it makes sense to you.

General guidelines for a good profile would be something like this:

Temperature ramp up 1ºC/second

Peak temperature should be 200C to 210C

Remain above liquidus (183C) for 45-75seconds

Do not heat any packages above 220C since this will most likely destroy the IC

Here is a good document that will help you with the profile as well. BGA-Reflow-Rework.pdf You now see where it would be very difficult to achieve this type of tight and timeline dependent profile with a heatgun.