We don’t suggest you using 2 HDD at the same time. It might over MAX current value for ESPRESSObin.
Have you ever tried other PC? I try putty on windows system and follow the instruction, system is able to boot up normally. I think your issue is related to PC setting.
Globalscale’s standard power supply is 12V/2A with 5.5mm*2.10mm*10mm connector.
The uboot you used was for older board. GTI kept updating uboot version there.
The PCIe slot on Espressobin is for WIFI and BT usage only. It doesn’t support mSATA.
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