Found the first bug in the board and it's a doozy.
The 12V0_EN line isn't actually wired to the supervisor, so the supervisor has no way to actually turn power on to any of the other rails. Oops.
I can work around this by using serial console on the power board and manually running "output forceon" to turn it on, so it's not the end of the world (and I could add a pullup on the PCB to make it come up automatically if needed). But still annoying.
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Andrew Zonenberg
In response to this post12V rail isn't shorted, there's only a miniscule increase in power consumption when I turn it on. But the VCCINT rail isn't coming up (according to the supervisor).
Time to dig deeper.
VCCINT measures 1.3 ohms to ground. That sounds... not healthy.
Betting it's a solder defect, the paste print there was not very good.
Time to hot air off the DC-DC and see if it clears the short, I guess?
I don't think it's the FPGA, it tested good earlier in the day and I baked it for quite a while before reflow just to make sure.
by Andrew Zonenberg ;
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