try systemd-analyze critical-chain to look at the bootup sequence. Then systemctl status <unit-file> to gather the locations of the individual unit files.
@wyleu Thanks! That’s exactly the sort of guide I was looking for to wrap my head around how things work.
I’m happy to report that after receiving a new sound card from Jose my Zynthian 4.5 kit is up a running! So it was definitely a bad sound card.
Interestingly, when I compared the old and new sound card I noticed that the old one has this funny “jumper wire” (red arrow in pic below) on it that the new one doesn’t. Does anybody know why this wire would be in the previous card I received and not in the new one? Could this be the source of the problems?
Hi @pmags , good news !
Regarding the wire, it looks that routing the 5V output from the Pi to the U3 voltage regulator has been forgotten in early batch of ZynADAC.
On its github repo I can see design changes 6 month ago.
I do not have right now Kicad to check these changes.
This is totally right, @le51 ! This piece of wire was added to fix a problem that was introduced due to last-minute modifications because of the chip crisis. In detail:
We produced and tested the first samples of ZynADAC by november 2020 and everything was fine. When we wanted to mass-produce, about january 2021, some parts were impossible to find, so we had to change the design on-the-fly and risk on mass-production without testing. Chip shortage was worstening, so going on another testing cycle wasn’t an option. We risked and we lost! Luckily the only issue was a “missing via” that was easily fixed by adding this little piece of wire on every card.
If you have one of this little jewels … you are lucky!! It’s hand-crafted by @jofemodo itself 
, and believe me, it doesn’t affect in anyway to the quality of sound you will get.
Anyway, @pmags, i would like to know if your problem with this ZynADAC is due to bad soldering from my part (on the photo everything seems OK) or anything else. So, if you agree on sending it back to me, i would really appreciate it.
Thanks!
Some kind of collector more or less 
@pmags you’re a happy guy !! 
More seriously @jofemodo , how is it going now with components shortage ? Have you tried to order a new batch of some zynthian hw stuff ? Is it still so complicated ?
Not sure if it’s a digital artifact but I could swear one of the chips looks cracked in that photo…
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Yeahhh man! Good eyes!! After zooming the photo, it really seems like the PCM5242 is cracked like a nut.
Hi, @pmags, could you confirm this?
Anyway, you could still ship the board to me. I could recover the PCM1863 (ADC chip) that is very difficult to find on the current crisis-market. Or if you could desolder it with a hot-air-gun, simply ship it to me inside an envelope.
Thanks!
@jofemodo I don’t have a hand lens or microscope to examine it up close by eye – I see the “darker” line that’s visible in the photo but I can’t feel a crack with my finger nail or finger tip. So I’m not sure if it’s actually cracked or not.
I’m happy to arrange to send you the board if you contact me via email. Please reach out via the email contact I provided for the replacement you sent me.