These are three problematic components on this particular motherboard - U4, U5 and U6. They're DC-DC voltage regulators and found just off the BMC chip
View attachment 29080
These are
incredibly prone to breakage. If the BMC does not initialize properly - the board will not boot, rendering it useless. After using the board for a while I had recommended it to quite a few folks. Of these - two had problems with the board not booting after some PCIe component install and one had a problem with a H12SSL that they were installing from new-in-box . All these could be traced back to one of these components breaking off. Knowing this I then moved my H12SSL from a Norco chassis to a Supermicro chassis. I was extra careful with it but very recently, I had to install and flash a few NIC cards and at some point - the board stopped working. As you can see, there's damage to the U4 component. Keep in mind I was careful so that should tell you how delicate this component is. These will break even if you put what can be considered normal pressure with your fingers.
Like I mentioned earlier - read the thread linked to earlier:
https://forums.servethehome.com/index.php?threads/h12ssl-i-stuck-at-bmc-initiating.38043/ - where several folks have had the exact same issue. Supermicro has almost always repaired free of charge but you do have to send the motherboard back for repairs and you do have to pay for shipping to SM.
Maybe the components were from a bad batch - don't know but I've stopped using or recommending the H12SSL series.
