To follow the recommendation from other users in this thread the yellow capacitor on the pictures few post before is the guilty (4700uf 10v yellow colored radial capacitor). If you don't find the same capacitor you can go with another with same capacity but higher tension. Just go with it if your case has to do with the power supply unit.
In other cases we have problems with the "security board" which is part of the mother board but this can be only solved in the repair center which has the original part to replace. So it make sense to try the capacitor replacement first before considering worst case scenario.