Is anyone familiar enough with the ODAC to identify what I burnt up?
Must have hooked up the power supply to my speaker amp incorrectly. Amp works fine still, but ODAC got sizzled.
It looks (emphasis on "looks") like a simple ferrite. That makes sense coming directly off of the USB power connection, too. This is just a guess, but looking at the other parts sizes on the PCB, it may be an 805 series ferrite such as this:
Again, just a guess. I'm fairly certain it's a ferrite - just the size that has me guessing. There are some much larger SMD parts on the PCB. I'm guessing those are 1206. Knowing that his YoYoDyne subcontractor's design used 603 parts in many places - that part appears to be sized in-between. That's why I'm guessing 805.
A ferrite bead would make sense, since the part number is "FB102" ;)
The ODAC schematic confirms it's a ferrite bead, but has no more details. I suppose it's not critical.
Note that the bead is on the ground rail. It kind of acts like a fuse. If it blew, you probably have a short between the V+ rail and ground. Before disassembling anything, it may be wise to use a DMM to check if the rails are currently shorted. If it's shorted by a stand-off or anything inside the build, you won't know it once the board is out and will never find the source of the problem. Talking from experience here, it's very frustrating.
I was able to get some help from George at Yoyodyne Consulting and yes, it is a ferrite. He had me bypass the spot to see if the damage went further, and from the limited testing I could do it doesn't look like the board is recoverable. I am sending it to him for a post mortem. He was incredibly responsive and generous with his time.
Well this in unfortunate. Was it a brand new dac, on it's first power-up?
If it's not a manufacturing error, then it may be useful to figure the source of the problem and make it public, just in case someone else runs into the same problem...
But then the ODAC isn't even a DIY project, so what do I know...
No, this ODAC had been functioning beautifully for several months. I was hooking it up to a new speaker amp and when I powered up it fried. I think something in the chain was improperly grounded, probably the power supply (I have had issues with the PSU before that I THOUGHT I had figured out, apparently not). Completely something on my end - not the ODAC.