[MinnowBoard] no suitable video mode found booting in blind mode

[John Hawley]

On 05/21/2015 08:26 AM, Ken Tait wrote:
> There is one other trick you can try to verify that this is the real
> problem with your setup.
> 
> place a switch in the + line of the wallwart going to the barrel jack.
> 
> Turn switch off, plug in barrel jack, plug in wall wart. Wait 5 seconds,
> then turn on the switch. It the board comes up then the supply is right
> on the edge of being large enough.  What you are doing with this test is
> allowing the wallwart to come up to full voltage and charge it's caps
> before applying a load to it.

Agreed, there are a number of power supplies that may be marginal in
general.  You can find our, paper napkin math, assumptions on power draw:

http://elinux.org/Minnowboard:MinnowMax#Power_Plug

along with some recommended power supplies.  That being said we've got
some internal folks who power the board off a good 2.1A usb port, so
obviously your mileage is going to vary.

That being said, I don't think the issue you are describing is really
power related, as I'd suspect the CPU has settled down a bit by that
point anyway.  I also have a memory of someone else reporting something
similar so I need to go back and look to see how this got resolved.

> Another thing I noticed here on all these boards is that the software on
> boot is not quite right..Someone is making the ASSumption that things
> turn on instantaneously in hardware so the software has no or minimal
> delays on boot. This needs to change. For this type of setup there
> should be a stall delay of at least 800ms on first power application
> before it checks for a boot device or anything else..

Well the assumptions that are being made in the firmware are the ones
being laid out by the respective specs for the interface (usb, sd, sata,
etc), and to date I haven't seen or had a report of storage having a
spin up time problem (like you are describing, and recommending an 800ms
delay).  I'd actually love to know what devices you've got that are
causing problems for you, as that might be more indicative of other
problems, where the delay would just mask the issue.

- John 'Warthog9' Hawley