Which is the board you’re developing on? Is it a Breakout Board or a custom board? Have you tried with a newer firmware version?
Regarding the two spots that you mention, are these based on the suggestions of this guide Intel® Edison Boards — Custom Expansion Board Tips?
It is a custom board. After getting in touch with an engineer at Intel it turns out that the handling of the PWRBTN# and RESET_OUT# changed between firmware versions 2.0 and 2.1:
- If RESET_OUT# is not pulled high the outputs on the Edison will remain in an unknown state
- PWRBTN# is now being handled in software and needs to be pulled high for the Edison to reliably boot
After a lot of searching I haven't been able to find any references to this behaviour in any of the documentation. I have a new PCB with these changes out for production and will know if it resolved the problem in a couple of days.