Path: ...!weretis.net!feeder8.news.weretis.net!newsfeed.xs3.de!nntp-feed.chiark.greenend.org.uk!ewrotcd!.POSTED.chiark.greenend.org.uk!not-for-mail From: Theo Newsgroups: comp.sys.raspberry-pi Subject: Re: Homebrew pi400 Date: 11 Dec 2024 18:10:07 +0000 (GMT) Organization: University of Cambridge, England Message-ID: <34s*FvN1z@news.chiark.greenend.org.uk> References: <87v7wgw3sh.fsf@rpi3> <87v7vr40jj.fsf@rpi3> <87msh243xg.fsf@rpi3> <87wmg6qi9o.fsf@rpi3> Injection-Info: chiark.greenend.org.uk; posting-host="chiark.greenend.org.uk:93.93.131.173"; logging-data="22533"; mail-complaints-to="abuse@chiark.greenend.org.uk" User-Agent: tin/1.8.3-20070201 ("Scotasay") (UNIX) (Linux/5.10.0-28-amd64 (x86_64)) Originator: theom@chiark.greenend.org.uk ([93.93.131.173]) Bytes: 2396 Lines: 34 The Natural Philosopher wrote: > On 11/12/2024 16:46, Daniel wrote: > > Andy Burns 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. Theo