The use of the U1100 LTC3850 was in my opinion a wrong approach, at least for the HDD power supply.
This is in the later designs also changed considerably by making two separate 5V supply's.

It is simply too much for the U1100 to provide all 5v on the motherboard.
Usually it works fine especially if there is not used a hdd, but if this circuit receives a malfunction, because the hdd used too much, or fails, it can give more damage to other components on the board.
The result is often an irreparable or hard to repair problem with too much damage.

A better solution is to separate the HDD power supply of this circuit, and supply it with an additional LM2596 DC-DC converter module.
These are cheap on ebay to found, a small version as 2 amp is sufficient.