Sorry but those are two completely different problems, You have YLOD,which means one of your chips (CPU or RSX) is dead. What we have here is consoles with a sudden shutdown but good CPU and RSX,that is common on NAND consoles which you don't have. Also reflowing is a bad idea,Yes the heat will move things in the chip which will cause it to work for a bit but it's dead.. You will also dry the thermal paste underneath the heat spreader causing overheating. The proper solution for YLOD is to replace the dead chip with a good chip. Please don't spam about your YLOD,it's off topic and not the problem this topic is about.