did some research on the YLOD ( yellow light of death ) on the PS3
found out the thermal paste goes dry and some of the solder shifts, so you need a repair kit off ebay for about $15, I did use a xbox one and a heat gun
and strip it down to the motherboard , clean the CPU's / motherboard , keep the heatgun on low and heat the motherboard evenly , but hover over the CPUs for about 25 second , then let it cool completly , then apply thermal paste to the CPU's , then you can put it back together
I also upgraded the hardrive to a 500GB from a 60GB , you can back it up and swap it over or just put the new one in , it jsut wont remeber all your saved games etc
it wont always work but it did for me, do this at your own risk , and please keep it unplug from the power supply
after the cleaning
thermal paste applied