Im electronic Tech and i will explain this heating trick for you all .. its pretty simple , and logic ,
We Live in a world and times come that People Want their Electronics More Fast , , More Slim and Light Weight , And at a Maximum Low Cost Possible ,
Manufacturers Dont HAve other choice To Cut in Their Architectures EX: more slim HeatSinks , And They , Since approx 10 years Use LEAD FREE SOLDER as a production Standart ,
to be sure that you will understand the mechanic of theses situation think about an house foundation . when each Season change theses Foundation suffer from Stress , and the ground Move and twist and eventualy that will cause a lot of cracks in house wall ,
moderns laptops are exactly the same as an house , you can consider that ''seasons '' are When the laptop is cold and you boot it up , Then the CPU/GPU /Chipset became Hot , then you shutdown your laptop , and it become Cold , this result as ''Motherboard Stress'' TWisting like House ground and applying tension on parts soldered onto .
Same things Day after day , Weeks after week , and without any advice BAM , the day that your laptop no longer boot has come. , one of the 250 Solder Point under GPU/CPU have Cracked and this result as a non functionnal motherboard Sometime and MOST of times , it Can be caused Too by a non Cleaned Heatsink and the CPU/GPU have Overheated ,
. in these times the only way to fix this is to Resolder The CPU/GPU.. but , they have no other technique to do that exept by REFLOWING it , , A good thing its manufacturers use a lot of surface mounted parts , and Motherboards/All kinds of connectors /HArddrive Sockets , and in resuming ALL PARTS on a motherboard Resist At anHiger Temperature Than Solder used , So in Fact Cooking the motherboard in a conventional Oven after MAke sure that is NO DIRECT RADIANT HEAT at a specific Temperature and at a specific Time Will Resolder ALL parts on the board Including the one that have CRacked ,, and most of time Give a second life to your machine
for those that have only Put it on a Heat plate , and think your computer is Repaired , you have only Temporary Fixed it because the solder have Expended a litle bit , but for sure its will not last long time ,
Its pretty Simple to do , if you are resourceful but it require a minimum of Skills and knowledge in laptop disassembling ,
Hope that will help !