2 things stand out to me. 1. Fuses blow because of some abnormal condition downline. Often they do blow so that something more complex is 'protected' from harm by the abnormal condition. 2. Sony's implementation of BlueRay drives often involves 'pairing' the drive with the motherboard, certainly in PS3s swapping the connecting board attached to the drive chassis is an essential part of 'drive replacement'. I'd not be surprised if the same was necessary in PS4.
2 things stand out to me. 1. Fuses blow because of some abnormal condition downline. Often they do blow so that something more complex is 'protected' from harm by the abnormal condition. 2. Sony's implementation of BlueRay drives often involves 'pairing' the drive with the motherboard, certainly in PS3s swapping the connecting board attached to the drive chassis is an essential part of 'drive replacement'. I'd not be surprised if the same was necessary in PS4.