I know sony's lead free solder can be reflow with a heat gun, but what if I got it reballed with lead solder and it ylod, would i be able to reflow it with a heat gun? Or would the only way to fix it is have it reball again?
If you have Endless Electronics reball your PS3 they will give you a 2 year warranty on the repair, and they have a lifetime YLOD warranty if the original Sony warranty seal is still intact...
Heat Gun reflows are considered bad repairs however I've seen some of these repairs last over a years and are still playing.
I've also seen reballs fail. The position of the Power Supply on top of the mother board in the FAT PS3's was a bad design. In the later models CECHH01 and on design shifted to a smaller motherboard with an offset power supply. However they still had the solder failing issues. Even the new slim have this problem though the percentages of failures are much lower.
You can actually reflow with a heat gun several times and it could work weeks, months, years. The key is to keep the system as cool as possible and generate as much air flow as possible around the PS3. Also a digital infrared thermometer can get you to the correct temperature for solder to melt. My research says that's som where between 200 and 350 degrees. Which is dangerous because it's close the the fail temperature of other components.
Infrared reflows or Reball repairs are suppose to be better fixes however if the system gets hot enough the solders will still fail. And each reflow will make the solder harder to repair as well.
In short you can repair the YLOD or RLOD with a heat gun but it's risky, might not last long, and will be harder to repair next time the failure comes back. Really if you plan to heat gun your system have an external drive on hand to transfer all of your saves to so you can install them on your new PS3 when the old one finally does stop for good.