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Re: [LUG] Pi mystery


On 25/11/13 21:18, Gordon Henderson wrote:
> On Mon, 25 Nov 2013, Philip Hudson wrote:
>> My son's Raspberry Pi rev B boots from its 4GB SD card (Raspbian) only
>> intermittently. It was running fine at home before we shut down
>> (properly)
>> and disconnected it to take it to Exeter. At Exeter, to our not very
>> great
>> surprise, it again refused to boot. Paul helped us eliminate several
>> possibilities at the Pi Jam in Exeter on Saturday; here's the latest
>> update.
>> First to recap (well, it's a recap for Paul), at the Pi Jam, with Paul's
>> help, we tried the following (all failed to do anything but show the
>> board's ROM start screen):
> There is no ROM startup screen.
>> * Different power adapter
>> * Different card, same board
>> * Different board (Paul's, also a Rev B), same card
>> * Mount and check our card on Paul's board booting from Paul's card,
>> using
>> Paul's USB card reader
>> So we gave up and enjoyed checking out everyone else's geeky stuff,
>> and it
>> was great, and we went home, and we plugged everything back in the
>> way it
>> was in the morning, and it booted and ran fine first time.
>> So, I conclude, that the explanation is one of the following:
>> 1. Our board likes using analog composite video out, which is what we
>> have
>> here, a bit more (but not enough to be deterministic even here) than
>> digital HDMI-to-DVI-D which is what we had in Exeter; or
> If using HDMI, then the target device must be enabled and turned on
> *before* you power up the Pi. The Pi detects the presence of a working
> HDMI capable device in milliseconds after power up and if it doesn't
> detect one, it will switch to compost video output.

This was the case, i powered down my own pi,  unplugged the power lead, 
plugged in phils sd card and then powered it back up again.


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