Can anybody help and say why so many MB are out of work because of the capacitors which blow ?? [usualy after guarantee period...]?? is that because they [capacitors] are bad?, or could it be because hot air from CPU heatsink is heating them ??
Usually the capacitors fail because they're cheap and/or defective from the start. There was a HORRIBLE run of capacitors from an overseas vendor back in 2005-2008 that was used in literally millions of cheap eMachines, HP, and Gateway computers (the boards were usually made by Asus, MSI, and FIC for OEM use) You don't see capacitor failure much any more these days on modern machines. They used a cheap electrolyte that broke down rapidly, and excess heat and high duty cycles caused them to fail at an astounding rate.