Sujet : Re: Homebrew pi400
De : tnp (at) *nospam* invalid.invalid (The Natural Philosopher)
Groupes : comp.sys.raspberry-piDate : 14. Dec 2024, 14:56:15
Autres entêtes
Organisation : A little, after lunch
Message-ID : <vjk2pv$nd7$8@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11
User-Agent : Mozilla Thunderbird
On 13/12/2024 23:55, Daniel wrote:
Theo <theom+news@chiark.greenend.org.uk> writes:
Theo <theom+news@chiark.greenend.org.uk> wrote:
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 11/12/2024 16:46, Daniel wrote:
Andy Burns <usenet@andyburns.uk> writes:
>
Daniel wrote:
>
Jeff did a teardown on his second channel and soldered a m.2 socket
hoping it was properly designed. He found the power lines weren't traced
in so no power.
>
There were some nearby component missing too, maybe the Rev1 board has
bugs, and they need a Rev2 (or whatever) but his soldering job looked
relatively clumsy (bridged pins etc).
>
Yeah, it was pretty bad, at least he was honest about it.
>
I am sure things were missing to keep the circuitry disabled and I'm no
engineer.
>
Why would you put support chips on if you were not going to install an
M.2 socket anyway?
>
I think he called it right in that this is a bare bones model, and more
upmarket versions will emerge in due course.
>
Looking at:
https://www.jeffgeerling.com/sites/default/files/images/pi-500-m2-socket-install.jpg
https://www.jeffgeerling.com/sites/default/files/images/pi-500-pcb-bottom.jpeg
>
I think there's a MOSFET and some decoupling capacitors missing (to the left
of the middle larger hole), so the power isn't connected. There may be a
pair of missing capacitors in series with the PCIe lane, but I can't
immediately see the footprints for those.
>
Ah, I see them now. To the right of the spot on the silver chip are four
tiny spots for passives, oriented at compass bearing 135 degrees. I can't
tell from the photo or video whether they're populated or not, but those
will be the series capacitors.
>
Theo
I'm going to wait for someone to hack a working solution then copy
it.
Wait for the Pi 501...with it all one the board already
-- Canada is all right really, though not for the whole weekend."Saki"